diff --git a/src/app/app.h b/src/app/app.h
index 5ea9f8107..240546915 100644
--- a/src/app/app.h
+++ b/src/app/app.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_APP_H_INCLUDED
 #define APP_APP_H_INCLUDED
+#pragma once
 
 #include "base/signal.h"
 #include "base/string.h"
diff --git a/src/app/app_menus.h b/src/app/app_menus.h
index f7ed25fad..e8f51a85c 100644
--- a/src/app/app_menus.h
+++ b/src/app/app_menus.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_APP_MENUS_H_INCLUDED
 #define APP_APP_MENUS_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include "base/unique_ptr.h"
diff --git a/src/app/app_options.h b/src/app/app_options.h
index fa7b4dc62..83e3355c4 100644
--- a/src/app/app_options.h
+++ b/src/app/app_options.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_APP_OPTIONS_H_INCLUDED
 #define APP_APP_OPTIONS_H_INCLUDED
+#pragma once
 
 #include <stdexcept>
 #include <string>
diff --git a/src/app/backup.h b/src/app/backup.h
index 240f8ea78..2c8fc309e 100644
--- a/src/app/backup.h
+++ b/src/app/backup.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_BACKUP_H_INCLUDED
 #define APP_BACKUP_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include "base/string.h"
diff --git a/src/app/check_update.h b/src/app/check_update.h
index 734943245..87e798c4b 100644
--- a/src/app/check_update.h
+++ b/src/app/check_update.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_CHECK_UPDATE_H_INCLUDED
 #define APP_CHECK_UPDATE_H_INCLUDED
+#pragma once
 
 #ifdef ENABLE_UPDATER
 
diff --git a/src/app/color.h b/src/app/color.h
index 3c775c922..a3b8e7273 100644
--- a/src/app/color.h
+++ b/src/app/color.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COLOR_H_INCLUDED
 #define APP_COLOR_H_INCLUDED
+#pragma once
 
 #include "raster/color.h"
 #include "raster/pixel_format.h"
diff --git a/src/app/color_picker.h b/src/app/color_picker.h
index 7a7a109d7..31cd7a265 100644
--- a/src/app/color_picker.h
+++ b/src/app/color_picker.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COLOR_PICKER_H_INCLUDED
 #define APP_COLOR_PICKER_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 
diff --git a/src/app/color_swatches.h b/src/app/color_swatches.h
index a7230b29f..426310f1a 100644
--- a/src/app/color_swatches.h
+++ b/src/app/color_swatches.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COLOR_SWATCHES_H_INCLUDED
 #define APP_COLOR_SWATCHES_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/app/color_utils.h b/src/app/color_utils.h
index cb0e23925..764062bdd 100644
--- a/src/app/color_utils.h
+++ b/src/app/color_utils.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COLOR_UTILS_H_INCLUDED
 #define APP_COLOR_UTILS_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "raster/color.h"
diff --git a/src/app/commands/cmd_export_sprite_sheet.h b/src/app/commands/cmd_export_sprite_sheet.h
index 8b2b4a3e1..f68ec9dd5 100644
--- a/src/app/commands/cmd_export_sprite_sheet.h
+++ b/src/app/commands/cmd_export_sprite_sheet.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_CMD_EXPORT_SPRITE_SHEET_H_INCLUDED
 #define APP_COMMANDS_CMD_EXPORT_SPRITE_SHEET_H_INCLUDED
+#pragma once
 
 #include "app/commands/command.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/commands/cmd_flip.h b/src/app/commands/cmd_flip.h
index d15bde8d2..1a434a35c 100644
--- a/src/app/commands/cmd_flip.h
+++ b/src/app/commands/cmd_flip.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_CMD_FLIP_H_INCLUDED
 #define APP_COMMANDS_CMD_FLIP_H_INCLUDED
+#pragma once
 
 #include "app/commands/command.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/commands/cmd_save_file.h b/src/app/commands/cmd_save_file.h
index a6b479179..aa6b08db0 100644
--- a/src/app/commands/cmd_save_file.h
+++ b/src/app/commands/cmd_save_file.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_CMD_SAVE_FILE_H_INCLUDED
 #define APP_COMMANDS_CMD_SAVE_FILE_H_INCLUDED
+#pragma once
 
 #include "app/commands/command.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/commands/command.h b/src/app/commands/command.h
index c8a7d7441..4988db3d7 100644
--- a/src/app/commands/command.h
+++ b/src/app/commands/command.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_COMMAND_H_INCLUDED
 #define APP_COMMANDS_COMMAND_H_INCLUDED
+#pragma once
 
 #include "app/commands/command_factory.h"
 
diff --git a/src/app/commands/command_factory.h b/src/app/commands/command_factory.h
index 20d34547d..a239cab7c 100644
--- a/src/app/commands/command_factory.h
+++ b/src/app/commands/command_factory.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_COMMAND_FACTORY_H_INCLUDED
 #define APP_COMMANDS_COMMAND_FACTORY_H_INCLUDED
+#pragma once
 
 namespace app {
   class Command;
diff --git a/src/app/commands/commands.h b/src/app/commands/commands.h
index 768f6624c..737b01426 100644
--- a/src/app/commands/commands.h
+++ b/src/app/commands/commands.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_COMMANDS_H_INCLUDED
 #define APP_COMMANDS_COMMANDS_H_INCLUDED
+#pragma once
 
 #include "ui/base.h"
 
diff --git a/src/app/commands/filters/color_curve_editor.h b/src/app/commands/filters/color_curve_editor.h
index 09a8c4cba..969d133cb 100644
--- a/src/app/commands/filters/color_curve_editor.h
+++ b/src/app/commands/filters/color_curve_editor.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_FILTERS_COLOR_CURVE_EDITOR_H_INCLUDED
 #define APP_COMMANDS_FILTERS_COLOR_CURVE_EDITOR_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/app/commands/filters/convolution_matrix_stock.h b/src/app/commands/filters/convolution_matrix_stock.h
index ac978a495..eba965e0a 100644
--- a/src/app/commands/filters/convolution_matrix_stock.h
+++ b/src/app/commands/filters/convolution_matrix_stock.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_FILTERS_CONVOLUTION_MATRIX_STOCK_H_INCLUDED
 #define APP_COMMANDS_FILTERS_CONVOLUTION_MATRIX_STOCK_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/app/commands/filters/filter_manager_impl.h b/src/app/commands/filters/filter_manager_impl.h
index cf7f95509..e310a7ee1 100644
--- a/src/app/commands/filters/filter_manager_impl.h
+++ b/src/app/commands/filters/filter_manager_impl.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_FILTERS_FILTER_MANAGER_IMPL_H_INCLUDED
 #define APP_COMMANDS_FILTERS_FILTER_MANAGER_IMPL_H_INCLUDED
+#pragma once
 
 #include "app/document_location.h"
 #include "base/exception.h"
diff --git a/src/app/commands/filters/filter_preview.h b/src/app/commands/filters/filter_preview.h
index f4c3fc7e8..79833b3d4 100644
--- a/src/app/commands/filters/filter_preview.h
+++ b/src/app/commands/filters/filter_preview.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_FILTERS_FILTER_PREVIEW_H_INCLUDED
 #define APP_COMMANDS_FILTERS_FILTER_PREVIEW_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/timer.h"
diff --git a/src/app/commands/filters/filter_target_buttons.h b/src/app/commands/filters/filter_target_buttons.h
index ebb0956da..ec0f7c2b1 100644
--- a/src/app/commands/filters/filter_target_buttons.h
+++ b/src/app/commands/filters/filter_target_buttons.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_FILTERS_FILTER_TARGET_BUTTONS_H_INCLUDED
 #define APP_COMMANDS_FILTERS_FILTER_TARGET_BUTTONS_H_INCLUDED
+#pragma once
 
 #include "base/signal.h"
 #include "filters/target.h"
diff --git a/src/app/commands/filters/filter_window.h b/src/app/commands/filters/filter_window.h
index cd325757c..aef529149 100644
--- a/src/app/commands/filters/filter_window.h
+++ b/src/app/commands/filters/filter_window.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_FILTERS_FILTER_WINDOW_H_INCLUDED
 #define APP_COMMANDS_FILTERS_FILTER_WINDOW_H_INCLUDED
+#pragma once
 
 #include "app/commands/filters/filter_preview.h"
 #include "app/commands/filters/filter_target_buttons.h"
diff --git a/src/app/commands/filters/filter_worker.h b/src/app/commands/filters/filter_worker.h
index 92cab04f5..06813b044 100644
--- a/src/app/commands/filters/filter_worker.h
+++ b/src/app/commands/filters/filter_worker.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_COMMANDS_FILTERS_FILTER_BG_H_INCLUDED
 #define APP_COMMANDS_FILTERS_FILTER_BG_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/console.h b/src/app/console.h
index 6ebd62cc3..35706cc3e 100644
--- a/src/app/console.h
+++ b/src/app/console.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_CONSOLE_H_INCLUDED
 #define APP_CONSOLE_H_INCLUDED
+#pragma once
 
 #include <exception>
 
diff --git a/src/app/context.h b/src/app/context.h
index d3eaa7a59..1de054295 100644
--- a/src/app/context.h
+++ b/src/app/context.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_CONTEXT_H_INCLUDED
 #define APP_CONTEXT_H_INCLUDED
+#pragma once
 
 #include "app/context_flags.h"
 #include "app/context_observer.h"
diff --git a/src/app/context_access.h b/src/app/context_access.h
index be11fc47a..a773a4747 100644
--- a/src/app/context_access.h
+++ b/src/app/context_access.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_CONTEXT_ACCESS_H_INCLUDED
 #define APP_CONTEXT_ACCESS_H_INCLUDED
+#pragma once
 
 #include "app/document_access.h"
 #include "app/document_location.h"
diff --git a/src/app/context_flags.h b/src/app/context_flags.h
index a40f53a1f..838ef7c6c 100644
--- a/src/app/context_flags.h
+++ b/src/app/context_flags.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_CONTEXT_FLAGS_H_INCLUDED
 #define APP_CONTEXT_FLAGS_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/context_observer.h b/src/app/context_observer.h
index 93a307a47..e2e907309 100644
--- a/src/app/context_observer.h
+++ b/src/app/context_observer.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_CONTEXT_OBSERVER_H_INCLUDED
 #define APP_CONTEXT_OBSERVER_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/context_observer_list.h b/src/app/context_observer_list.h
index 37136125c..9b2cd7a18 100644
--- a/src/app/context_observer_list.h
+++ b/src/app/context_observer_list.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_CONTEXT_OBSERVER_LIST_H_INCLUDED
 #define APP_CONTEXT_OBSERVER_LIST_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/app/data_recovery.h b/src/app/data_recovery.h
index 282c20db3..1df1ce2fd 100644
--- a/src/app/data_recovery.h
+++ b/src/app/data_recovery.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DATA_RECOVERY_H_INCLUDED
 #define APP_DATA_RECOVERY_H_INCLUDED
+#pragma once
 
 #include "app/context_observer.h"
 #include "app/document_observer.h"
diff --git a/src/app/document.h b/src/app/document.h
index 0b95b0235..af840d211 100644
--- a/src/app/document.h
+++ b/src/app/document.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENT_H_INCLUDED
 #define APP_DOCUMENT_H_INCLUDED
+#pragma once
 
 #include "app/document_id.h"
 #include "base/disable_copying.h"
diff --git a/src/app/document_access.h b/src/app/document_access.h
index b75752bca..a8ce47e2e 100644
--- a/src/app/document_access.h
+++ b/src/app/document_access.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENT_ACCESS_H_INCLUDED
 #define APP_DOCUMENT_ACCESS_H_INCLUDED
+#pragma once
 
 #include "base/exception.h"
 #include "app/context.h"
diff --git a/src/app/document_api.h b/src/app/document_api.h
index 53af87a69..d6e6a16fd 100644
--- a/src/app/document_api.h
+++ b/src/app/document_api.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENT_API_H_INCLUDED
 #define APP_DOCUMENT_API_H_INCLUDED
+#pragma once
 
 #include "gfx/rect.h"
 #include "raster/algorithm/flip_type.h"
diff --git a/src/app/document_event.h b/src/app/document_event.h
index 021938109..c031390fe 100644
--- a/src/app/document_event.h
+++ b/src/app/document_event.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENT_EVENT_H_INCLUDED
 #define APP_DOCUMENT_EVENT_H_INCLUDED
+#pragma once
 
 #include "gfx/region.h"
 #include "raster/frame_number.h"
diff --git a/src/app/document_exporter.h b/src/app/document_exporter.h
index 911138bc9..434478c1f 100644
--- a/src/app/document_exporter.h
+++ b/src/app/document_exporter.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENT_EXPORTER_H_INCLUDED
 #define APP_DOCUMENT_EXPORTER_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include "gfx/fwd.h"
diff --git a/src/app/document_id.h b/src/app/document_id.h
index b1dc19e6a..7377b649f 100644
--- a/src/app/document_id.h
+++ b/src/app/document_id.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENT_ID_H_INCLUDED
 #define APP_DOCUMENT_ID_H_INCLUDED
+#pragma once
 
 #include "doc/object_id.h"
 
diff --git a/src/app/document_location.h b/src/app/document_location.h
index c712309fc..1feae9e92 100644
--- a/src/app/document_location.h
+++ b/src/app/document_location.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENT_LOCATION_H_INCLUDED
 #define APP_DOCUMENT_LOCATION_H_INCLUDED
+#pragma once
 
 #include "raster/frame_number.h"
 #include "raster/layer_index.h"
diff --git a/src/app/document_observer.h b/src/app/document_observer.h
index 0d6e9646b..416ad1d91 100644
--- a/src/app/document_observer.h
+++ b/src/app/document_observer.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENT_OBSERVER_H_INCLUDED
 #define APP_DOCUMENT_OBSERVER_H_INCLUDED
+#pragma once
 
 #include "raster/frame_number.h"
 
diff --git a/src/app/document_undo.h b/src/app/document_undo.h
index 329fc78e4..7cbd00920 100644
--- a/src/app/document_undo.h
+++ b/src/app/document_undo.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENT_UNDO_H_INCLUDED
 #define APP_DOCUMENT_UNDO_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/disable_copying.h"
diff --git a/src/app/documents.h b/src/app/documents.h
index 86200abc5..d29a3ab35 100644
--- a/src/app/documents.h
+++ b/src/app/documents.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOCUMENTS_H_INCLUDED
 #define APP_DOCUMENTS_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include "app/document_id.h"
diff --git a/src/app/file/file.h b/src/app/file/file.h
index 749dd3c92..463776467 100644
--- a/src/app/file/file.h
+++ b/src/app/file/file.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_FILE_FILE_H_INCLUDED
 #define APP_FILE_FILE_H_INCLUDED
+#pragma once
 
 #include "base/shared_ptr.h"
 #include "raster/frame_number.h"
diff --git a/src/app/file/file_format.h b/src/app/file/file_format.h
index 0400fadf7..0d342f568 100644
--- a/src/app/file/file_format.h
+++ b/src/app/file/file_format.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_FILE_FILE_FORMAT_H_INCLUDED
 #define APP_FILE_FILE_FORMAT_H_INCLUDED
+#pragma once
 
 #include "base/shared_ptr.h"
 
diff --git a/src/app/file/file_formats_manager.h b/src/app/file/file_formats_manager.h
index baae5bf44..03a4c2972 100644
--- a/src/app/file/file_formats_manager.h
+++ b/src/app/file/file_formats_manager.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_FILE_FILE_FORMATS_MANAGER_H_INCLUDED
 #define APP_FILE_FILE_FORMATS_MANAGER_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/app/file/fli/fli.h b/src/app/file/fli/fli.h
index b088ab19b..b3ed3e484 100644
--- a/src/app/file/fli/fli.h
+++ b/src/app/file/fli/fli.h
@@ -18,6 +18,7 @@
  */
 #ifndef APP_FILE_FLI_FLI_H_INCLUDED
 #define APP_FILE_FLI_FLI_H_INCLUDED
+#pragma once
 
 /** structures */
 
diff --git a/src/app/file/format_options.h b/src/app/file/format_options.h
index 0c385c6d2..2809433dd 100644
--- a/src/app/file/format_options.h
+++ b/src/app/file/format_options.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_FILE_FORMAT_OPTIONS_H_INCLUDED
 #define APP_FILE_FORMAT_OPTIONS_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/file_selector.h b/src/app/file_selector.h
index c9d75d15b..e459fb0ec 100644
--- a/src/app/file_selector.h
+++ b/src/app/file_selector.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_FILE_SELECTOR_H_INCLUDED
 #define APP_FILE_SELECTOR_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 
diff --git a/src/app/file_system.h b/src/app/file_system.h
index ff90a9e21..750b89ead 100644
--- a/src/app/file_system.h
+++ b/src/app/file_system.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_FILE_SYSTEM_H_INCLUDED
 #define APP_FILE_SYSTEM_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 
diff --git a/src/app/find_widget.h b/src/app/find_widget.h
index 5bc1b4f78..ee247638a 100644
--- a/src/app/find_widget.h
+++ b/src/app/find_widget.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_FIND_WIDGET_H_INCLUDED
 #define APP_FIND_WIDGET_H_INCLUDED
+#pragma once
 
 #include "app/widget_not_found.h"
 #include "ui/widget.h"
diff --git a/src/app/flatten.h b/src/app/flatten.h
index 272dc006b..165e47e79 100644
--- a/src/app/flatten.h
+++ b/src/app/flatten.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_FLATTEN_H_INCLUDED
 #define APP_FLATTEN_H_INCLUDED
+#pragma once
 
 #include "gfx/rect.h"
 #include "raster/frame_number.h"
diff --git a/src/app/gfxmode.h b/src/app/gfxmode.h
index 802c97a78..cf3fb2bb9 100644
--- a/src/app/gfxmode.h
+++ b/src/app/gfxmode.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_GFXMODE_H_INCLUDED
 #define APP_GFXMODE_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/gui_xml.h b/src/app/gui_xml.h
index 7491b00d6..67ec3140d 100644
--- a/src/app/gui_xml.h
+++ b/src/app/gui_xml.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_GUI_XML_INCLUDED
 #define APP_GUI_XML_INCLUDED
+#pragma once
 
 #include "app/xml_document.h"
 #include "base/string.h"
diff --git a/src/app/ini_file.h b/src/app/ini_file.h
index 12c5df77b..4dca0d54c 100644
--- a/src/app/ini_file.h
+++ b/src/app/ini_file.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_INI_FILE_H_INCLUDED
 #define APP_INI_FILE_H_INCLUDED
+#pragma once
 
 #include <allegro/config.h>
 #include "gfx/rect.h"
diff --git a/src/app/job.h b/src/app/job.h
index 28846c58c..1a32bea6f 100644
--- a/src/app/job.h
+++ b/src/app/job.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_JOB_H_INCLUDED
 #define APP_JOB_H_INCLUDED
+#pragma once
 
 #include "base/unique_ptr.h"
 #include "ui/alert.h"
diff --git a/src/app/launcher.h b/src/app/launcher.h
index 869a440ac..af1ebaf67 100644
--- a/src/app/launcher.h
+++ b/src/app/launcher.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_LAUNCHER_H_INCLUDED
 #define APP_LAUNCHER_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/app/load_widget.h b/src/app/load_widget.h
index 6e4018d60..0b283a4a3 100644
--- a/src/app/load_widget.h
+++ b/src/app/load_widget.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_LOAD_WIDGET_H_INCLUDED
 #define APP_LOAD_WIDGET_H_INCLUDED
+#pragma once
 
 #include "app/widget_loader.h"
 #include "base/unique_ptr.h"
diff --git a/src/app/log.h b/src/app/log.h
index 812915981..4ea6107cb 100644
--- a/src/app/log.h
+++ b/src/app/log.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_LOG_H_INCLUDED
 #define APP_LOG_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/modules.h b/src/app/modules.h
index f6c02c31a..491e2033e 100644
--- a/src/app/modules.h
+++ b/src/app/modules.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_MODULES_H_INCLUDED
 #define APP_MODULES_H_INCLUDED
+#pragma once
 
 #include "ui/base.h"
 
diff --git a/src/app/modules/editors.h b/src/app/modules/editors.h
index 521e41643..e57580e59 100644
--- a/src/app/modules/editors.h
+++ b/src/app/modules/editors.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_MODULES_EDITORS_H_INCLUDED
 #define APP_MODULES_EDITORS_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/modules/gfx.h b/src/app/modules/gfx.h
index 53bac81c8..58c0a7f2f 100644
--- a/src/app/modules/gfx.h
+++ b/src/app/modules/gfx.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_MODULES_GFX_H_INCLUDED
 #define APP_MODULES_GFX_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "gfx/rect.h"
diff --git a/src/app/modules/gui.h b/src/app/modules/gui.h
index bc89851c9..885b9c190 100644
--- a/src/app/modules/gui.h
+++ b/src/app/modules/gui.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_MODULES_GUI_H_INCLUDED
 #define APP_MODULES_GUI_H_INCLUDED
+#pragma once
 
 #include "app/ui/skin/skin_property.h"
 #include "base/exception.h"
diff --git a/src/app/modules/palettes.h b/src/app/modules/palettes.h
index 733968b76..bb7f97516 100644
--- a/src/app/modules/palettes.h
+++ b/src/app/modules/palettes.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_MODULES_PALETTES_H_INCLUDED
 #define APP_MODULES_PALETTES_H_INCLUDED
+#pragma once
 
 namespace raster {
   class Palette;
diff --git a/src/app/objects_container_impl.h b/src/app/objects_container_impl.h
index efccdf749..275280d5f 100644
--- a/src/app/objects_container_impl.h
+++ b/src/app/objects_container_impl.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_DOC_OBJECTS_CONTAINER_H_INCLUDED
 #define APP_DOC_OBJECTS_CONTAINER_H_INCLUDED
+#pragma once
 
 #include "undo/objects_container.h"
 
diff --git a/src/app/project.h b/src/app/project.h
index 02315596d..64194843c 100644
--- a/src/app/project.h
+++ b/src/app/project.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_PROJECT_H_INCLUDED
 #define APP_PROJECT_H_INCLUDED
+#pragma once
 
 #include "app/project_observer.h"
 #include "base/disable_copying.h"
diff --git a/src/app/project_event.h b/src/app/project_event.h
index 37078df92..70147e526 100644
--- a/src/app/project_event.h
+++ b/src/app/project_event.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_PROJECT_EVENT_H_INCLUDED
 #define APP_PROJECT_EVENT_H_INCLUDED
+#pragma once
 
 namespace app {
   class Document;
diff --git a/src/app/project_observer.h b/src/app/project_observer.h
index a976bbfa5..bd018719d 100644
--- a/src/app/project_observer.h
+++ b/src/app/project_observer.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_PROJECT_OBSERVER_H_INCLUDED
 #define APP_PROJECT_OBSERVER_H_INCLUDED
+#pragma once
 
 #include "app/project_event.h"
 
diff --git a/src/app/recent_files.h b/src/app/recent_files.h
index abc9aae49..f7bb0ad27 100644
--- a/src/app/recent_files.h
+++ b/src/app/recent_files.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_RECENT_FILES_H_INCLUDED
 #define APP_RECENT_FILES_H_INCLUDED
+#pragma once
 
 #include "base/recent_items.h"
 #include "base/string.h"
diff --git a/src/app/resource_finder.h b/src/app/resource_finder.h
index ee0c9fbb7..2a8d437f9 100644
--- a/src/app/resource_finder.h
+++ b/src/app/resource_finder.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_RESOURCE_FINDER_H_INCLUDED
 #define APP_RESOURCE_FINDER_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <vector>
diff --git a/src/app/settings/document_settings.h b/src/app/settings/document_settings.h
index f54df3cd1..9ae4ef432 100644
--- a/src/app/settings/document_settings.h
+++ b/src/app/settings/document_settings.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_SETTINGS_DOCUMENT_SETTINGS_H_INCLUDED
 #define APP_SETTINGS_DOCUMENT_SETTINGS_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "filters/tiled_mode.h"
diff --git a/src/app/settings/freehand_algorithm.h b/src/app/settings/freehand_algorithm.h
index 744cd381d..a756023dc 100644
--- a/src/app/settings/freehand_algorithm.h
+++ b/src/app/settings/freehand_algorithm.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_SETTINGS_FREEHAND_ALGORITHM_H_INCLUDED
 #define APP_SETTINGS_FREEHAND_ALGORITHM_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/settings/ink_type.h b/src/app/settings/ink_type.h
index 8826c8a38..1ef953d1e 100644
--- a/src/app/settings/ink_type.h
+++ b/src/app/settings/ink_type.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_SETTINGS_INK_TYPE_H_INCLUDED
 #define APP_SETTINGS_INK_TYPE_H_INCLUDED
+#pragma once
 
 namespace app {
   
diff --git a/src/app/settings/rotation_algorithm.h b/src/app/settings/rotation_algorithm.h
index 17a8f0c7f..e4e100b28 100644
--- a/src/app/settings/rotation_algorithm.h
+++ b/src/app/settings/rotation_algorithm.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_SETTINGS_ROTATION_ALGORITHM_H_INCLUDED
 #define APP_SETTINGS_ROTATION_ALGORITHM_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/settings/selection_mode.h b/src/app/settings/selection_mode.h
index 1f0bb87fe..5f0343b2d 100644
--- a/src/app/settings/selection_mode.h
+++ b/src/app/settings/selection_mode.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_SETTINGS_SELECTION_MODE_H_INCLUDED
 #define APP_SETTINGS_SELECTION_MODE_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/settings/settings.h b/src/app/settings/settings.h
index 2a7d101d5..d2e0e8180 100644
--- a/src/app/settings/settings.h
+++ b/src/app/settings/settings.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_SETTINGS_SETTINGS_H_INCLUDED
 #define APP_SETTINGS_SETTINGS_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "app/settings/freehand_algorithm.h"
diff --git a/src/app/settings/settings_observers.h b/src/app/settings/settings_observers.h
index 0e025b53a..e0f75ac8d 100644
--- a/src/app/settings/settings_observers.h
+++ b/src/app/settings/settings_observers.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_SETTINGS_SETTINGS_OBSERVERS_H_INCLUDED
 #define APP_SETTINGS_SETTINGS_OBSERVERS_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "app/settings/freehand_algorithm.h"
diff --git a/src/app/settings/ui_settings_impl.h b/src/app/settings/ui_settings_impl.h
index 1adb35a94..d6f925ebf 100644
--- a/src/app/settings/ui_settings_impl.h
+++ b/src/app/settings/ui_settings_impl.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_SETTINGS_UI_SETTINGS_H_INCLUDED
 #define APP_SETTINGS_UI_SETTINGS_H_INCLUDED
+#pragma once
 
 #include <map>
 #include <string>
diff --git a/src/app/shell.h b/src/app/shell.h
index 41b9723e1..494b9bb79 100644
--- a/src/app/shell.h
+++ b/src/app/shell.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_SHELL_H_INCLUDED
 #define APP_SHELL_H_INCLUDED
+#pragma once
 
 namespace scripting {
   class Engine;
diff --git a/src/app/thumbnail_generator.h b/src/app/thumbnail_generator.h
index 50385d83e..aea319934 100644
--- a/src/app/thumbnail_generator.h
+++ b/src/app/thumbnail_generator.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_THUMBNAIL_GENERATOR_H_INCLUDED
 #define APP_THUMBNAIL_GENERATOR_H_INCLUDED
+#pragma once
 
 #include "base/mutex.h"
 #include "base/unique_ptr.h"
diff --git a/src/app/tools/controller.h b/src/app/tools/controller.h
index 4f9cb92a1..ba4c18c4b 100644
--- a/src/app/tools/controller.h
+++ b/src/app/tools/controller.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_CONTROLLER_H_INCLUDED
 #define APP_TOOLS_CONTROLLER_H_INCLUDED
+#pragma once
 
 #include "gfx/point.h"
 
diff --git a/src/app/tools/fill.h b/src/app/tools/fill.h
index 59aad9462..69f862aa5 100644
--- a/src/app/tools/fill.h
+++ b/src/app/tools/fill.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_FILL_H_INCLUDED
 #define APP_TOOLS_FILL_H_INCLUDED
+#pragma once
 
 namespace app {
   namespace tools {
diff --git a/src/app/tools/ink.h b/src/app/tools/ink.h
index 4e07ce16f..03b2dda41 100644
--- a/src/app/tools/ink.h
+++ b/src/app/tools/ink.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_INK_H_INCLUDED
 #define APP_TOOLS_INK_H_INCLUDED
+#pragma once
 
 namespace app {
   namespace tools {
diff --git a/src/app/tools/intertwine.h b/src/app/tools/intertwine.h
index 6b8376361..5978ef1fc 100644
--- a/src/app/tools/intertwine.h
+++ b/src/app/tools/intertwine.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_INTERTWINE_H_INCLUDED
 #define APP_TOOLS_INTERTWINE_H_INCLUDED
+#pragma once
 
 #include "gfx/point.h"
 
diff --git a/src/app/tools/pick_ink.h b/src/app/tools/pick_ink.h
index 6d18b8f5b..e14536c67 100644
--- a/src/app/tools/pick_ink.h
+++ b/src/app/tools/pick_ink.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_PICK_INK_H_INCLUDED
 #define APP_TOOLS_PICK_INK_H_INCLUDED
+#pragma once
 
 #include "app/tools/ink.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/tools/point_shape.h b/src/app/tools/point_shape.h
index 7932b1ef0..d96fbd4ac 100644
--- a/src/app/tools/point_shape.h
+++ b/src/app/tools/point_shape.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_TOOL_POINT_SHAPE_INCLUDED
 #define APP_TOOLS_TOOL_POINT_SHAPE_H_INCLUDED
+#pragma once
 
 #include "gfx/rect.h"
 
diff --git a/src/app/tools/shade_table.h b/src/app/tools/shade_table.h
index f0a30ec3d..5d99b853f 100644
--- a/src/app/tools/shade_table.h
+++ b/src/app/tools/shade_table.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_SHADE_TABLE_H_INCLUDED
 #define APP_TOOLS_SHADE_TABLE_H_INCLUDED
+#pragma once
 
 #include "app/tools/shading_mode.h"
 #include <vector>
diff --git a/src/app/tools/shading_mode.h b/src/app/tools/shading_mode.h
index 7c9a6453a..074741e55 100644
--- a/src/app/tools/shading_mode.h
+++ b/src/app/tools/shading_mode.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_SHADING_MODE_H_INCLUDED
 #define APP_TOOLS_SHADING_MODE_H_INCLUDED
+#pragma once
 
 namespace app {
   namespace tools {
diff --git a/src/app/tools/shading_options.h b/src/app/tools/shading_options.h
index f550ea28a..7151f5b3c 100644
--- a/src/app/tools/shading_options.h
+++ b/src/app/tools/shading_options.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_SHADING_OPTIONS_H_INCLUDED
 #define APP_TOOLS_SHADING_OPTIONS_H_INCLUDED
+#pragma once
 
 namespace app {
   namespace tools {
diff --git a/src/app/tools/tool.h b/src/app/tools/tool.h
index 1319a98dd..b8b006645 100644
--- a/src/app/tools/tool.h
+++ b/src/app/tools/tool.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_TOOL_H_INCLUDED
 #define APP_TOOLS_TOOL_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/app/tools/tool_box.h b/src/app/tools/tool_box.h
index eaa92df27..27aaf8717 100644
--- a/src/app/tools/tool_box.h
+++ b/src/app/tools/tool_box.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_TOOL_BOX_H_INCLUDED
 #define APP_TOOLS_TOOL_BOX_H_INCLUDED
+#pragma once
 
 #include <list>
 #include <map>
diff --git a/src/app/tools/tool_group.h b/src/app/tools/tool_group.h
index 4d7641ecd..3658338ab 100644
--- a/src/app/tools/tool_group.h
+++ b/src/app/tools/tool_group.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_TOOL_GROUP_H_INCLUDED
 #define APP_TOOLS_TOOL_GROUP_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/app/tools/tool_loop.h b/src/app/tools/tool_loop.h
index 26526a26d..5e66ca980 100644
--- a/src/app/tools/tool_loop.h
+++ b/src/app/tools/tool_loop.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_TOOL_LOOP_H_INCLUDED
 #define APP_TOOLS_TOOL_LOOP_H_INCLUDED
+#pragma once
 
 #include "app/settings/selection_mode.h"
 #include "app/tools/trace_policy.h"
diff --git a/src/app/tools/tool_loop_manager.h b/src/app/tools/tool_loop_manager.h
index 3adb801d3..290cf5584 100644
--- a/src/app/tools/tool_loop_manager.h
+++ b/src/app/tools/tool_loop_manager.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_TOOL_LOOP_MANAGER_H_INCLUDED
 #define APP_TOOLS_TOOL_LOOP_MANAGER_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/app/tools/trace_policy.h b/src/app/tools/trace_policy.h
index 1b9f4a0e6..ebd675f56 100644
--- a/src/app/tools/trace_policy.h
+++ b/src/app/tools/trace_policy.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_TOOLS_TRACE_POLICY_H_INCLUDED
 #define APP_TOOLS_TRACE_POLICY_H_INCLUDED
+#pragma once
 
 namespace app {
   namespace tools {
diff --git a/src/app/ui/app_menuitem.h b/src/app/ui/app_menuitem.h
index 923e3b2f0..90ca7435b 100644
--- a/src/app/ui/app_menuitem.h
+++ b/src/app/ui/app_menuitem.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_APP_MENUITEM_H_INCLUDED
 #define APP_UI_APP_MENUITEM_H_INCLUDED
+#pragma once
 
 #include "ui/menu.h"
 
diff --git a/src/app/ui/button_set.h b/src/app/ui/button_set.h
index 20c38ecd0..018ad335c 100644
--- a/src/app/ui/button_set.h
+++ b/src/app/ui/button_set.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_BUTTON_SET_H_INCLUDED
 #define APP_UI_BUTTON_SET_H_INCLUDED
+#pragma once
 
 #include "base/signal.h"
 #include "ui/box.h"
diff --git a/src/app/ui/color_bar.h b/src/app/ui/color_bar.h
index 165fdd135..bda4688b8 100644
--- a/src/app/ui/color_bar.h
+++ b/src/app/ui/color_bar.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_COLOR_BAR_H_INCLUDED
 #define APP_UI_COLOR_BAR_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "app/ui/color_button.h"
diff --git a/src/app/ui/color_button.h b/src/app/ui/color_button.h
index d8fdcbf80..44a3e0e5a 100644
--- a/src/app/ui/color_button.h
+++ b/src/app/ui/color_button.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_COLOR_BUTTON_H_INCLUDED
 #define APP_UI_COLOR_BUTTON_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/ui/color_selector.h b/src/app/ui/color_selector.h
index d0d5db206..0867cdb56 100644
--- a/src/app/ui/color_selector.h
+++ b/src/app/ui/color_selector.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_COLOR_SELECTOR_H_INCLUDED
 #define APP_UI_COLOR_SELECTOR_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "app/ui/color_sliders.h"
diff --git a/src/app/ui/color_sliders.h b/src/app/ui/color_sliders.h
index e9b70a26b..4542cce48 100644
--- a/src/app/ui/color_sliders.h
+++ b/src/app/ui/color_sliders.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_COLOR_SLIDERS_H_INCLUDED
 #define APP_UI_COLOR_SLIDERS_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/ui/context_bar.h b/src/app/ui/context_bar.h
index 3728f3325..b0596b318 100644
--- a/src/app/ui/context_bar.h
+++ b/src/app/ui/context_bar.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_CONTEXT_BAR_H_INCLUDED
 #define APP_UI_CONTEXT_BAR_H_INCLUDED
+#pragma once
 
 #include "app/settings/settings_observers.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/ui/document_view.h b/src/app/ui/document_view.h
index 9c85671dd..507ec67f0 100644
--- a/src/app/ui/document_view.h
+++ b/src/app/ui/document_view.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_DOCUMENT_VIEW_H_INCLUDED
 #define APP_UI_DOCUMENT_VIEW_H_INCLUDED
+#pragma once
 
 #include "app/document_observer.h"
 #include "app/ui/tabs.h"
diff --git a/src/app/ui/drop_down_button.h b/src/app/ui/drop_down_button.h
index ad3a0b19f..c8a6af8f7 100644
--- a/src/app/ui/drop_down_button.h
+++ b/src/app/ui/drop_down_button.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_DROP_DOWN_BUTTON_H_INCLUDED
 #define APP_UI_DROP_DOWN_BUTTON_H_INCLUDED
+#pragma once
 
 #include "base/signal.h"
 #include "ui/box.h"
diff --git a/src/app/ui/editor/drawing_state.h b/src/app/ui/editor/drawing_state.h
index c21acc43b..ad3d37ad7 100644
--- a/src/app/ui/editor/drawing_state.h
+++ b/src/app/ui/editor/drawing_state.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_DRAWING_STATE_H_INCLUDED
 #define APP_UI_EDITOR_DRAWING_STATE_H_INCLUDED
+#pragma once
 
 #include "app/ui/editor/standby_state.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/ui/editor/editor.h b/src/app/ui/editor/editor.h
index 4e7d1ed8c..241516a28 100644
--- a/src/app/ui/editor/editor.h
+++ b/src/app/ui/editor/editor.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_H_INCLUDED
 #define APP_UI_EDITOR_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "app/document.h"
diff --git a/src/app/ui/editor/editor_customization_delegate.h b/src/app/ui/editor/editor_customization_delegate.h
index 52de30dbe..e5cde3e78 100644
--- a/src/app/ui/editor/editor_customization_delegate.h
+++ b/src/app/ui/editor/editor_customization_delegate.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_CUSTOMIZATION_DELEGATE_H_INCLUDED
 #define APP_UI_EDITOR_CUSTOMIZATION_DELEGATE_H_INCLUDED
+#pragma once
 
 namespace tools {
   class Tool;
diff --git a/src/app/ui/editor/editor_decorator.h b/src/app/ui/editor/editor_decorator.h
index 61486fa2f..566b39434 100644
--- a/src/app/ui/editor/editor_decorator.h
+++ b/src/app/ui/editor/editor_decorator.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_EDITOR_DECORATOR_H_INCLUDED
 #define APP_UI_EDITOR_EDITOR_DECORATOR_H_INCLUDED
+#pragma once
 
 #include "gfx/rect.h"
 
diff --git a/src/app/ui/editor/editor_observer.h b/src/app/ui/editor/editor_observer.h
index 37b4c5f05..0d2137310 100644
--- a/src/app/ui/editor/editor_observer.h
+++ b/src/app/ui/editor/editor_observer.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_OBSERVER_H_INCLUDED
 #define APP_UI_EDITOR_OBSERVER_H_INCLUDED
+#pragma once
 
 namespace app {
   
diff --git a/src/app/ui/editor/editor_observers.h b/src/app/ui/editor/editor_observers.h
index 4b4fca148..970d7b939 100644
--- a/src/app/ui/editor/editor_observers.h
+++ b/src/app/ui/editor/editor_observers.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_OBSERVERS_H_INCLUDED
 #define APP_UI_EDITOR_OBSERVERS_H_INCLUDED
+#pragma once
 
 #include "app/ui/editor/editor_observer.h"
 #include "base/observers.h"
diff --git a/src/app/ui/editor/editor_state.h b/src/app/ui/editor/editor_state.h
index 0f6f8af2f..13203919c 100644
--- a/src/app/ui/editor/editor_state.h
+++ b/src/app/ui/editor/editor_state.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_EDITOR_STATE_H_INCLUDED
 #define APP_UI_EDITOR_EDITOR_STATE_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include "base/shared_ptr.h"
diff --git a/src/app/ui/editor/editor_states_history.h b/src/app/ui/editor/editor_states_history.h
index 001919475..783b62b2e 100644
--- a/src/app/ui/editor/editor_states_history.h
+++ b/src/app/ui/editor/editor_states_history.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_STATES_HISTORY_H_INCLUDED
 #define APP_UI_EDITOR_STATES_HISTORY_H_INCLUDED
+#pragma once
 
 #include "app/ui/editor/editor_state.h"
 
diff --git a/src/app/ui/editor/editor_view.h b/src/app/ui/editor/editor_view.h
index 7147e88f8..7db5fc039 100644
--- a/src/app/ui/editor/editor_view.h
+++ b/src/app/ui/editor/editor_view.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_VIEW_H_INCLUDED
 #define APP_UI_EDITOR_VIEW_H_INCLUDED
+#pragma once
 
 #include "ui/view.h"
 #include "app/settings/settings_observers.h"
diff --git a/src/app/ui/editor/handle_type.h b/src/app/ui/editor/handle_type.h
index 9045cd561..73ad0b1dc 100644
--- a/src/app/ui/editor/handle_type.h
+++ b/src/app/ui/editor/handle_type.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_HANDLE_TYPE_H_INCLUDED
 #define APP_UI_EDITOR_HANDLE_TYPE_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/ui/editor/moving_cel_state.h b/src/app/ui/editor/moving_cel_state.h
index 5fcd12f3b..4b62e449a 100644
--- a/src/app/ui/editor/moving_cel_state.h
+++ b/src/app/ui/editor/moving_cel_state.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_MOVING_CEL_STATE_H_INCLUDED
 #define APP_UI_EDITOR_MOVING_CEL_STATE_H_INCLUDED
+#pragma once
 
 #include "app/ui/editor/standby_state.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/ui/editor/moving_pixels_state.h b/src/app/ui/editor/moving_pixels_state.h
index a42fd26f1..4174e6220 100644
--- a/src/app/ui/editor/moving_pixels_state.h
+++ b/src/app/ui/editor/moving_pixels_state.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_MOVING_PIXELS_STATE_H_INCLUDED
 #define APP_UI_EDITOR_MOVING_PIXELS_STATE_H_INCLUDED
+#pragma once
 
 #include "app/context_observer.h"
 #include "app/settings/settings_observers.h"
diff --git a/src/app/ui/editor/pixels_movement.h b/src/app/ui/editor/pixels_movement.h
index 98bc7743a..40e8c79fe 100644
--- a/src/app/ui/editor/pixels_movement.h
+++ b/src/app/ui/editor/pixels_movement.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_PIXELS_MOVEMENT_H_INCLUDED
 #define APP_UI_EDITOR_PIXELS_MOVEMENT_H_INCLUDED
+#pragma once
 
 #include "app/context_access.h"
 #include "app/settings/settings_observers.h"
diff --git a/src/app/ui/editor/ruler.h b/src/app/ui/editor/ruler.h
index e2ac78ce1..8a1902730 100644
--- a/src/app/ui/editor/ruler.h
+++ b/src/app/ui/editor/ruler.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_RULER_H_INCLUDED
 #define APP_UI_EDITOR_RULER_H_INCLUDED
+#pragma once
 
 namespace app {
 
diff --git a/src/app/ui/editor/scrolling_state.h b/src/app/ui/editor/scrolling_state.h
index d141a5ce0..029918a30 100644
--- a/src/app/ui/editor/scrolling_state.h
+++ b/src/app/ui/editor/scrolling_state.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_SCROLLING_STATE_H_INCLUDED
 #define APP_UI_EDITOR_SCROLLING_STATE_H_INCLUDED
+#pragma once
 
 #include "app/ui/editor/editor_state.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/ui/editor/select_box_state.h b/src/app/ui/editor/select_box_state.h
index efcc2cd1a..7ed39c9d1 100644
--- a/src/app/ui/editor/select_box_state.h
+++ b/src/app/ui/editor/select_box_state.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_SELECT_BOX_STATE_H_INCLUDED
 #define APP_UI_EDITOR_SELECT_BOX_STATE_H_INCLUDED
+#pragma once
 
 #include "app/ui/editor/editor_decorator.h"
 #include "app/ui/editor/ruler.h"
diff --git a/src/app/ui/editor/standby_state.h b/src/app/ui/editor/standby_state.h
index 1e3fbae60..a87e82c81 100644
--- a/src/app/ui/editor/standby_state.h
+++ b/src/app/ui/editor/standby_state.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_STANDBY_STATE_H_INCLUDED
 #define APP_UI_EDITOR_STANDBY_STATE_H_INCLUDED
+#pragma once
 
 #include "app/ui/editor/editor_decorator.h"
 #include "app/ui/editor/editor_state.h"
diff --git a/src/app/ui/editor/tool_loop_impl.h b/src/app/ui/editor/tool_loop_impl.h
index 39f6612b8..c877f45be 100644
--- a/src/app/ui/editor/tool_loop_impl.h
+++ b/src/app/ui/editor/tool_loop_impl.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_TOOL_LOOP_IMPL_H_INCLUDED
 #define APP_UI_EDITOR_TOOL_LOOP_IMPL_H_INCLUDED
+#pragma once
 
 namespace ui {
   class MouseMessage;
diff --git a/src/app/ui/editor/transform_handles.h b/src/app/ui/editor/transform_handles.h
index 5a24eaab9..e01f1c04d 100644
--- a/src/app/ui/editor/transform_handles.h
+++ b/src/app/ui/editor/transform_handles.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_EDITOR_TRANSFORM_HANDLES_H_INCLUDED
 #define APP_UI_EDITOR_TRANSFORM_HANDLES_H_INCLUDED
+#pragma once
 
 #include "app/ui/editor/handle_type.h"
 #include "gfx/point.h"
diff --git a/src/app/ui/file_list.h b/src/app/ui/file_list.h
index f6d2d5e47..8763b30c9 100644
--- a/src/app/ui/file_list.h
+++ b/src/app/ui/file_list.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_FILE_LIST_H_INCLUDED
 #define APP_UI_FILE_LIST_H_INCLUDED
+#pragma once
 
 #include "app/file_system.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/ui/file_selector.h b/src/app/ui/file_selector.h
index 4f4368de5..2ae5f859f 100644
--- a/src/app/ui/file_selector.h
+++ b/src/app/ui/file_selector.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_FILE_SELECTOR_H_INCLUDED
 #define APP_UI_FILE_SELECTOR_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 #include "base/unique_ptr.h"
diff --git a/src/app/ui/hex_color_entry.h b/src/app/ui/hex_color_entry.h
index a3e04b28c..95baff4c5 100644
--- a/src/app/ui/hex_color_entry.h
+++ b/src/app/ui/hex_color_entry.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_HEX_COLOR_ENTRY_H_INCLUDED
 #define APP_UI_HEX_COLOR_ENTRY_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "base/signal.h"
diff --git a/src/app/ui/main_menu_bar.h b/src/app/ui/main_menu_bar.h
index da8160f38..ed4cc7f70 100644
--- a/src/app/ui/main_menu_bar.h
+++ b/src/app/ui/main_menu_bar.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_MAIN_MENU_BAR_H_INCLUDED
 #define APP_UI_MAIN_MENU_BAR_H_INCLUDED
+#pragma once
 
 #include "ui/menu.h"
 
diff --git a/src/app/ui/main_window.h b/src/app/ui/main_window.h
index 89e3ffc06..0fb017a1d 100644
--- a/src/app/ui/main_window.h
+++ b/src/app/ui/main_window.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_MAIN_WINDOW_H_INCLUDED
 #define APP_UI_MAIN_WINDOW_H_INCLUDED
+#pragma once
 
 #include "app/ui/tabs.h"
 #include "ui/window.h"
diff --git a/src/app/ui/mini_editor.h b/src/app/ui/mini_editor.h
index d9d68de2c..3e4f25c9e 100644
--- a/src/app/ui/mini_editor.h
+++ b/src/app/ui/mini_editor.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_MINI_EDITOR_VIEW_H_INCLUDED
 #define APP_UI_MINI_EDITOR_VIEW_H_INCLUDED
+#pragma once
 
 #include "app/ui/document_view.h"
 #include "ui/timer.h"
diff --git a/src/app/ui/palette_view.h b/src/app/ui/palette_view.h
index 5a6c6dd1e..4211a3771 100644
--- a/src/app/ui/palette_view.h
+++ b/src/app/ui/palette_view.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_PALETTE_VIEW_H_INCLUDED
 #define APP_UI_PALETTE_VIEW_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/app/ui/popup_window_pin.h b/src/app/ui/popup_window_pin.h
index b187d8dfb..cec9e3669 100644
--- a/src/app/ui/popup_window_pin.h
+++ b/src/app/ui/popup_window_pin.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_POPUP_FRAME_PIN_H_INCLUDED
 #define APP_UI_POPUP_FRAME_PIN_H_INCLUDED
+#pragma once
 
 #include "ui/button.h"
 #include "ui/popup_window.h"
diff --git a/src/app/ui/skin/button_icon_impl.h b/src/app/ui/skin/button_icon_impl.h
index 3b517eaa5..e96a9bfcf 100644
--- a/src/app/ui/skin/button_icon_impl.h
+++ b/src/app/ui/skin/button_icon_impl.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_SKIN_BUTTON_ICON_IMPL_H_INCLUDED
 #define APP_UI_SKIN_BUTTON_ICON_IMPL_H_INCLUDED
+#pragma once
 
 #include "ui/button.h"
 
diff --git a/src/app/ui/skin/skin_button.h b/src/app/ui/skin/skin_button.h
index c1171f274..bb42a16be 100644
--- a/src/app/ui/skin/skin_button.h
+++ b/src/app/ui/skin/skin_button.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_SKIN_SKIN_BUTTON_H_INCLUDED
 #define APP_UI_SKIN_SKIN_BUTTON_H_INCLUDED
+#pragma once
 
 #include "app/ui/skin/skin_parts.h"
 #include "app/ui/skin/skin_theme.h"
diff --git a/src/app/ui/skin/skin_part.h b/src/app/ui/skin/skin_part.h
index 626d67828..d1d06f932 100644
--- a/src/app/ui/skin/skin_part.h
+++ b/src/app/ui/skin/skin_part.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_SKIN_SKIN_PART_H_INCLUDED
 #define APP_UI_SKIN_SKIN_PART_H_INCLUDED
+#pragma once
 
 #include <vector>
 #include "base/shared_ptr.h"
diff --git a/src/app/ui/skin/skin_parts.h b/src/app/ui/skin/skin_parts.h
index e8a0e50dd..d2442a68a 100644
--- a/src/app/ui/skin/skin_parts.h
+++ b/src/app/ui/skin/skin_parts.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_SKIN_SKIN_PARTS_H_INCLUDED
 #define APP_UI_SKIN_SKIN_PARTS_H_INCLUDED
+#pragma once
 
 namespace app {
   namespace skin {
diff --git a/src/app/ui/skin/skin_property.h b/src/app/ui/skin/skin_property.h
index 00ad4e4dd..6f79c3e33 100644
--- a/src/app/ui/skin/skin_property.h
+++ b/src/app/ui/skin/skin_property.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_SKIN_SKIN_PROPERTY_H_INCLUDED
 #define APP_UI_SKIN_SKIN_PROPERTY_H_INCLUDED
+#pragma once
 
 #include "base/shared_ptr.h"
 #include "ui/property.h"
diff --git a/src/app/ui/skin/skin_slider_property.h b/src/app/ui/skin/skin_slider_property.h
index 3c128cb4c..6c5132571 100644
--- a/src/app/ui/skin/skin_slider_property.h
+++ b/src/app/ui/skin/skin_slider_property.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_SKIN_SKIN_SLIDER_PROPERTY_H_INCLUDED
 #define APP_UI_SKIN_SKIN_SLIDER_PROPERTY_H_INCLUDED
+#pragma once
 
 #include "app/ui/skin/skin_property.h"
 #include "base/shared_ptr.h"
diff --git a/src/app/ui/skin/skin_theme.h b/src/app/ui/skin/skin_theme.h
index 3c9a3d98b..7c762b560 100644
--- a/src/app/ui/skin/skin_theme.h
+++ b/src/app/ui/skin/skin_theme.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_SKIN_SKIN_THEME_H_INCLUDED
 #define APP_UI_SKIN_SKIN_THEME_H_INCLUDED
+#pragma once
 
 #include "app/ui/skin/skin_part.h"
 #include "app/ui/skin/skin_parts.h"
diff --git a/src/app/ui/skin/style.h b/src/app/ui/skin/style.h
index 84f323805..202cc220e 100644
--- a/src/app/ui/skin/style.h
+++ b/src/app/ui/skin/style.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_SKIN_STYLE_H_INCLUDED
 #define APP_UI_SKIN_STYLE_H_INCLUDED
+#pragma once
 
 #include "app/ui/skin/skin_part.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/ui/skin/style_sheet.h b/src/app/ui/skin/style_sheet.h
index 04b8ae2d0..dca49d96e 100644
--- a/src/app/ui/skin/style_sheet.h
+++ b/src/app/ui/skin/style_sheet.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_SKIN_STYLE_SHEET_H_INCLUDED
 #define APP_UI_SKIN_STYLE_SHEET_H_INCLUDED
+#pragma once
 
 #include "app/ui/skin/skin_part.h"
 #include "css/rule.h"
diff --git a/src/app/ui/start_view.h b/src/app/ui/start_view.h
index 7d308627d..8d72ae1be 100644
--- a/src/app/ui/start_view.h
+++ b/src/app/ui/start_view.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_START_VIEW_H_INCLUDED
 #define APP_UI_START_VIEW_H_INCLUDED
+#pragma once
 
 #include "app/ui/tabs.h"
 #include "app/ui/workspace_view.h"
diff --git a/src/app/ui/status_bar.h b/src/app/ui/status_bar.h
index 1abb33e6c..790ef23b9 100644
--- a/src/app/ui/status_bar.h
+++ b/src/app/ui/status_bar.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_STATUS_BAR_H_INCLUDED
 #define APP_UI_STATUS_BAR_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "base/compiler_specific.h"
diff --git a/src/app/ui/tabs.h b/src/app/ui/tabs.h
index a8b70a05e..1351214f5 100644
--- a/src/app/ui/tabs.h
+++ b/src/app/ui/tabs.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_TABS_H_INCLUDED
 #define APP_UI_TABS_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/mouse_buttons.h"
diff --git a/src/app/ui/timeline.h b/src/app/ui/timeline.h
index 263bb464d..363d15481 100644
--- a/src/app/ui/timeline.h
+++ b/src/app/ui/timeline.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_TIMELINE_H_INCLUDED
 #define APP_UI_TIMELINE_H_INCLUDED
+#pragma once
 
 #include "app/context_observer.h"
 #include "app/document_observer.h"
diff --git a/src/app/ui/toolbar.h b/src/app/ui/toolbar.h
index 87cfcaea9..d8b4dadc0 100644
--- a/src/app/ui/toolbar.h
+++ b/src/app/ui/toolbar.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_TOOLBAR_H_INCLUDED
 #define APP_UI_TOOLBAR_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "gfx/point.h"
diff --git a/src/app/ui/workspace.h b/src/app/ui/workspace.h
index 783bc8f0e..233ed0502 100644
--- a/src/app/ui/workspace.h
+++ b/src/app/ui/workspace.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_WORKSPACE_H_INCLUDED
 #define APP_UI_WORKSPACE_H_INCLUDED
+#pragma once
 
 #include "app/ui/workspace_views.h"
 #include "base/signal.h"
diff --git a/src/app/ui/workspace_part.h b/src/app/ui/workspace_part.h
index 92da8b5d9..d2423f8c9 100644
--- a/src/app/ui/workspace_part.h
+++ b/src/app/ui/workspace_part.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_WORKSPACE_PART_H_INCLUDED
 #define APP_UI_WORKSPACE_PART_H_INCLUDED
+#pragma once
 
 #include "app/ui/workspace_views.h"
 #include "ui/box.h"
diff --git a/src/app/ui/workspace_view.h b/src/app/ui/workspace_view.h
index e31b51ebc..c3e5f8d1b 100644
--- a/src/app/ui/workspace_view.h
+++ b/src/app/ui/workspace_view.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_WORKSPACE_VIEW_H_INCLUDED
 #define APP_UI_WORKSPACE_VIEW_H_INCLUDED
+#pragma once
 
 namespace ui {
   class Widget;
diff --git a/src/app/ui/workspace_views.h b/src/app/ui/workspace_views.h
index bca2bb27e..8111b61eb 100644
--- a/src/app/ui/workspace_views.h
+++ b/src/app/ui/workspace_views.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_WORKSPACE_VIEWS_H_INCLUDED
 #define APP_UI_WORKSPACE_VIEWS_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/app/ui_context.h b/src/app/ui_context.h
index ebe159848..b677f6094 100644
--- a/src/app/ui_context.h
+++ b/src/app/ui_context.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UI_CONTEXT_H_INCLUDED
 #define APP_UI_CONTEXT_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "app/context.h"
diff --git a/src/app/undo_transaction.h b/src/app/undo_transaction.h
index e350264a7..45b33010a 100644
--- a/src/app/undo_transaction.h
+++ b/src/app/undo_transaction.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDO_TRANSACTION_H_INCLUDED
 #define APP_UNDO_TRANSACTION_H_INCLUDED
+#pragma once
 
 #include "undo/modification.h"
 
diff --git a/src/app/undoers/add_cel.h b/src/app/undoers/add_cel.h
index 9ab1b7983..e90c7dd8d 100644
--- a/src/app/undoers/add_cel.h
+++ b/src/app/undoers/add_cel.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_ADD_CEL_H_INCLUDED
 #define APP_UNDOERS_ADD_CEL_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/add_frame.h b/src/app/undoers/add_frame.h
index da3d78eb5..f89c42981 100644
--- a/src/app/undoers/add_frame.h
+++ b/src/app/undoers/add_frame.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_ADD_FRAME_H_INCLUDED
 #define APP_UNDOERS_ADD_FRAME_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "raster/frame_number.h"
diff --git a/src/app/undoers/add_image.h b/src/app/undoers/add_image.h
index 1565eebb3..b52ecd23a 100644
--- a/src/app/undoers/add_image.h
+++ b/src/app/undoers/add_image.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_ADD_IMAGE_H_INCLUDED
 #define APP_UNDOERS_ADD_IMAGE_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/add_layer.h b/src/app/undoers/add_layer.h
index 6ee94f975..5c03fa289 100644
--- a/src/app/undoers/add_layer.h
+++ b/src/app/undoers/add_layer.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_ADD_LAYER_H_INCLUDED
 #define APP_UNDOERS_ADD_LAYER_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/add_palette.h b/src/app/undoers/add_palette.h
index 0fc0afa2c..89b8c81a1 100644
--- a/src/app/undoers/add_palette.h
+++ b/src/app/undoers/add_palette.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_ADD_PALETTE_H_INCLUDED
 #define APP_UNDOERS_ADD_PALETTE_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "raster/frame_number.h"
diff --git a/src/app/undoers/close_group.h b/src/app/undoers/close_group.h
index 624bd9ba2..5ecd7928a 100644
--- a/src/app/undoers/close_group.h
+++ b/src/app/undoers/close_group.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_CLOSE_GROUP_H_INCLUDED
 #define APP_UNDOERS_CLOSE_GROUP_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "raster/sprite_position.h"
diff --git a/src/app/undoers/dirty_area.h b/src/app/undoers/dirty_area.h
index 0d6a0b587..417cc4d51 100644
--- a/src/app/undoers/dirty_area.h
+++ b/src/app/undoers/dirty_area.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_DIRTY_AREA_H_INCLUDED
 #define APP_UNDOERS_DIRTY_AREA_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/flip_image.h b/src/app/undoers/flip_image.h
index 7c0e11abb..86570b63f 100644
--- a/src/app/undoers/flip_image.h
+++ b/src/app/undoers/flip_image.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_FLIP_IMAGE_H_INCLUDED
 #define APP_UNDOERS_FLIP_IMAGE_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "gfx/fwd.h"
diff --git a/src/app/undoers/image_area.h b/src/app/undoers/image_area.h
index b09ed6ee2..ea982dd72 100644
--- a/src/app/undoers/image_area.h
+++ b/src/app/undoers/image_area.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_IMAGE_AREA_H_INCLUDED
 #define APP_UNDOERS_IMAGE_AREA_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/move_layer.h b/src/app/undoers/move_layer.h
index 8848530bb..54296b2e4 100644
--- a/src/app/undoers/move_layer.h
+++ b/src/app/undoers/move_layer.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_MOVE_LAYER_H_INCLUDED
 #define APP_UNDOERS_MOVE_LAYER_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/object_io.h b/src/app/undoers/object_io.h
index 0bd941768..9226eeae8 100644
--- a/src/app/undoers/object_io.h
+++ b/src/app/undoers/object_io.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_OBJECT_IO_H_INCLUDED
 #define APP_UNDOERS_OBJECT_IO_H_INCLUDED
+#pragma once
 
 #include "base/serialization.h"
 #include "base/unique_ptr.h"
diff --git a/src/app/undoers/open_group.h b/src/app/undoers/open_group.h
index a5b643813..8ce3e0cad 100644
--- a/src/app/undoers/open_group.h
+++ b/src/app/undoers/open_group.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_OPEN_GROUP_H_INCLUDED
 #define APP_UNDOERS_OPEN_GROUP_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "raster/sprite_position.h"
diff --git a/src/app/undoers/remap_palette.h b/src/app/undoers/remap_palette.h
index 30c716af5..35dbd075d 100644
--- a/src/app/undoers/remap_palette.h
+++ b/src/app/undoers/remap_palette.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_REMAP_PALETTE_H_INCLUDED
 #define APP_UNDOERS_REMAP_PALETTE_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "raster/frame_number.h"
diff --git a/src/app/undoers/remove_cel.h b/src/app/undoers/remove_cel.h
index a31ce8560..2e5086709 100644
--- a/src/app/undoers/remove_cel.h
+++ b/src/app/undoers/remove_cel.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_REMOVE_CEL_H_INCLUDED
 #define APP_UNDOERS_REMOVE_CEL_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/remove_frame.h b/src/app/undoers/remove_frame.h
index de5579196..1c26f10b7 100644
--- a/src/app/undoers/remove_frame.h
+++ b/src/app/undoers/remove_frame.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_REMOVE_FRAME_H_INCLUDED
 #define APP_UNDOERS_REMOVE_FRAME_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "raster/frame_number.h"
diff --git a/src/app/undoers/remove_image.h b/src/app/undoers/remove_image.h
index ceb698cd0..dc9879131 100644
--- a/src/app/undoers/remove_image.h
+++ b/src/app/undoers/remove_image.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_REMOVE_IMAGE_H_INCLUDED
 #define APP_UNDOERS_REMOVE_IMAGE_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/remove_layer.h b/src/app/undoers/remove_layer.h
index e7eca41e7..7173cb366 100644
--- a/src/app/undoers/remove_layer.h
+++ b/src/app/undoers/remove_layer.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_REMOVE_LAYER_H_INCLUDED
 #define APP_UNDOERS_REMOVE_LAYER_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/remove_palette.h b/src/app/undoers/remove_palette.h
index 5d119c738..a81b78a96 100644
--- a/src/app/undoers/remove_palette.h
+++ b/src/app/undoers/remove_palette.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_REMOVE_PALETTE_H_INCLUDED
 #define APP_UNDOERS_REMOVE_PALETTE_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "raster/frame_number.h"
diff --git a/src/app/undoers/replace_image.h b/src/app/undoers/replace_image.h
index 6ad34823d..cc1b0775f 100644
--- a/src/app/undoers/replace_image.h
+++ b/src/app/undoers/replace_image.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_REPLACE_IMAGE_H_INCLUDED
 #define APP_UNDOERS_REPLACE_IMAGE_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/set_cel_frame.h b/src/app/undoers/set_cel_frame.h
index a377117fc..0d3a138d9 100644
--- a/src/app/undoers/set_cel_frame.h
+++ b/src/app/undoers/set_cel_frame.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_CEL_FRAME_H_INCLUDED
 #define APP_UNDOERS_SET_CEL_FRAME_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "raster/frame_number.h"
diff --git a/src/app/undoers/set_cel_opacity.h b/src/app/undoers/set_cel_opacity.h
index 229b61121..9725a6c61 100644
--- a/src/app/undoers/set_cel_opacity.h
+++ b/src/app/undoers/set_cel_opacity.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_CEL_OPACITY_H_INCLUDED
 #define APP_UNDOERS_SET_CEL_OPACITY_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/set_cel_position.h b/src/app/undoers/set_cel_position.h
index 252f95d04..09c91be12 100644
--- a/src/app/undoers/set_cel_position.h
+++ b/src/app/undoers/set_cel_position.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_CEL_POSITION_H_INCLUDED
 #define APP_UNDOERS_SET_CEL_POSITION_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/set_frame_duration.h b/src/app/undoers/set_frame_duration.h
index 01ec02f1e..db40d726a 100644
--- a/src/app/undoers/set_frame_duration.h
+++ b/src/app/undoers/set_frame_duration.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_FRAME_DURATION_H_INCLUDED
 #define APP_UNDOERS_SET_FRAME_DURATION_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "raster/frame_number.h"
diff --git a/src/app/undoers/set_layer_flags.h b/src/app/undoers/set_layer_flags.h
index 577b057ff..b606837f4 100644
--- a/src/app/undoers/set_layer_flags.h
+++ b/src/app/undoers/set_layer_flags.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_LAYER_FLAGS_H_INCLUDED
 #define APP_UNDOERS_SET_LAYER_FLAGS_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/set_layer_name.h b/src/app/undoers/set_layer_name.h
index 9aba5c2c6..f61581d45 100644
--- a/src/app/undoers/set_layer_name.h
+++ b/src/app/undoers/set_layer_name.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_LAYER_NAME_H_INCLUDED
 #define APP_UNDOERS_SET_LAYER_NAME_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/set_mask.h b/src/app/undoers/set_mask.h
index a5a8eae4c..368fcf59e 100644
--- a/src/app/undoers/set_mask.h
+++ b/src/app/undoers/set_mask.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_MASK_H_INCLUDED
 #define APP_UNDOERS_SET_MASK_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/set_mask_position.h b/src/app/undoers/set_mask_position.h
index fefddff5b..828c84cb7 100644
--- a/src/app/undoers/set_mask_position.h
+++ b/src/app/undoers/set_mask_position.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_MASK_POSITION_H_INCLUDED
 #define APP_UNDOERS_SET_MASK_POSITION_H_INCLUDED
+#pragma once
 
 #include "undo/object_id.h"
 #include "app/undoers/undoer_base.h"
diff --git a/src/app/undoers/set_palette_colors.h b/src/app/undoers/set_palette_colors.h
index 784d75381..09e1e5f71 100644
--- a/src/app/undoers/set_palette_colors.h
+++ b/src/app/undoers/set_palette_colors.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_PALETTE_COLORS_H_INCLUDED
 #define APP_UNDOERS_SET_PALETTE_COLORS_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "raster/frame_number.h"
diff --git a/src/app/undoers/set_sprite_pixel_format.h b/src/app/undoers/set_sprite_pixel_format.h
index 8f2de760d..1f66c82b6 100644
--- a/src/app/undoers/set_sprite_pixel_format.h
+++ b/src/app/undoers/set_sprite_pixel_format.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_SPRITE_PIXEL_FORMAT_H_INCLUDED
 #define APP_UNDOERS_SET_SPRITE_PIXEL_FORMAT_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/set_sprite_size.h b/src/app/undoers/set_sprite_size.h
index c2cbca3e3..239575073 100644
--- a/src/app/undoers/set_sprite_size.h
+++ b/src/app/undoers/set_sprite_size.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_SPRITE_SIZE_H_INCLUDED
 #define APP_UNDOERS_SET_SPRITE_SIZE_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/set_stock_pixel_format.h b/src/app/undoers/set_stock_pixel_format.h
index 051c100d7..0c91f8134 100644
--- a/src/app/undoers/set_stock_pixel_format.h
+++ b/src/app/undoers/set_stock_pixel_format.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_STOCK_PIXEL_FORMAT_H_INCLUDED
 #define APP_UNDOERS_SET_STOCK_PIXEL_FORMAT_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "undo/object_id.h"
diff --git a/src/app/undoers/set_total_frames.h b/src/app/undoers/set_total_frames.h
index 9ef9f315f..3419acc0c 100644
--- a/src/app/undoers/set_total_frames.h
+++ b/src/app/undoers/set_total_frames.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_SET_TOTAL_FRAMES_H_INCLUDED
 #define APP_UNDOERS_SET_TOTAL_FRAMES_H_INCLUDED
+#pragma once
 
 #include "app/undoers/undoer_base.h"
 #include "raster/frame_number.h"
diff --git a/src/app/undoers/undoer_base.h b/src/app/undoers/undoer_base.h
index f6cfb8611..ff25c25a7 100644
--- a/src/app/undoers/undoer_base.h
+++ b/src/app/undoers/undoer_base.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UNDOERS_UNDOER_BASE_H_INCLUDED
 #define APP_UNDOERS_UNDOER_BASE_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "undo/undoer.h"
diff --git a/src/app/util/autocrop.h b/src/app/util/autocrop.h
index 6f1a58c7a..616ca932f 100644
--- a/src/app/util/autocrop.h
+++ b/src/app/util/autocrop.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UTIL_AUTOCROP_H_INCLUDED
 #define APP_UTIL_AUTOCROP_H_INCLUDED
+#pragma once
 
 namespace raster {
   class Image;
diff --git a/src/app/util/boundary.h b/src/app/util/boundary.h
index 3762a4f19..5f8d0e3be 100644
--- a/src/app/util/boundary.h
+++ b/src/app/util/boundary.h
@@ -23,6 +23,7 @@
 
 #ifndef APP_UTIL_BOUNDARY_H_INCLUDED
 #define APP_UTIL_BOUNDARY_H_INCLUDED
+#pragma once
 
 namespace raster {
   class Image;  
diff --git a/src/app/util/celmove.h b/src/app/util/celmove.h
index ed75e1689..b466a251a 100644
--- a/src/app/util/celmove.h
+++ b/src/app/util/celmove.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UTIL_CELMOVE_H_INCLUDED
 #define APP_UTIL_CELMOVE_H_INCLUDED
+#pragma once
 
 #include "raster/frame_number.h"
 
diff --git a/src/app/util/clipboard.h b/src/app/util/clipboard.h
index 806faddb5..2711facf6 100644
--- a/src/app/util/clipboard.h
+++ b/src/app/util/clipboard.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UTIL_CLIPBOARD_H_INCLUDED
 #define APP_UTIL_CLIPBOARD_H_INCLUDED
+#pragma once
 
 #include "gfx/point.h"
 #include "gfx/size.h"
diff --git a/src/app/util/expand_cel_canvas.h b/src/app/util/expand_cel_canvas.h
index b01253b98..bb4bf9338 100644
--- a/src/app/util/expand_cel_canvas.h
+++ b/src/app/util/expand_cel_canvas.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UTIL_EXPAND_CEL_CANVAS_H_INCLUDED
 #define APP_UTIL_EXPAND_CEL_CANVAS_H_INCLUDED
+#pragma once
 
 #include "filters/tiled_mode.h"
 #include "gfx/rect.h"
diff --git a/src/app/util/filetoks.h b/src/app/util/filetoks.h
index 8ed0ddb5d..e0014fea5 100644
--- a/src/app/util/filetoks.h
+++ b/src/app/util/filetoks.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UTIL_FILETOKS_H_INCLUDED
 #define APP_UTIL_FILETOKS_H_INCLUDED
+#pragma once
 
 #include <stdio.h>
 
diff --git a/src/app/util/misc.h b/src/app/util/misc.h
index d51511e58..ac86dbcdc 100644
--- a/src/app/util/misc.h
+++ b/src/app/util/misc.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UTIL_MISC_H_INCLUDED
 #define APP_UTIL_MISC_H_INCLUDED
+#pragma once
 
 namespace raster {
   class Image;
diff --git a/src/app/util/msk_file.h b/src/app/util/msk_file.h
index d8fa3db25..abff80a45 100644
--- a/src/app/util/msk_file.h
+++ b/src/app/util/msk_file.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UTIL_MSK_FILE_H_INCLUDED
 #define APP_UTIL_MSK_FILE_H_INCLUDED
+#pragma once
 
 namespace raster {
   class Mask;
diff --git a/src/app/util/pic_file.h b/src/app/util/pic_file.h
index 6a338fe5c..cd2d3e7ca 100644
--- a/src/app/util/pic_file.h
+++ b/src/app/util/pic_file.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UTIL_PIC_FILE_H_INCLUDED
 #define APP_UTIL_PIC_FILE_H_INCLUDED
+#pragma once
 
 #include <allegro/color.h>
 
diff --git a/src/app/util/render.h b/src/app/util/render.h
index 070f3b4c0..70418bb8d 100644
--- a/src/app/util/render.h
+++ b/src/app/util/render.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_UTIL_RENDER_H_INCLUDED
 #define APP_UTIL_RENDER_H_INCLUDED
+#pragma once
 
 #include "app/color.h"
 #include "raster/frame_number.h"
diff --git a/src/app/webserver.h b/src/app/webserver.h
index 30a2c6a20..fefb25272 100644
--- a/src/app/webserver.h
+++ b/src/app/webserver.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_WEBSERVER_H_INCLUDED
 #define APP_WEBSERVER_H_INCLUDED
+#pragma once
 
 #ifdef ENABLE_WEBSERVER
 
diff --git a/src/app/widget_loader.h b/src/app/widget_loader.h
index ea4f32716..e103c17a0 100644
--- a/src/app/widget_loader.h
+++ b/src/app/widget_loader.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_WIDGET_LOADER_H_INCLUDED
 #define APP_WIDGET_LOADER_H_INCLUDED
+#pragma once
 
 #include "app/widget_type_mismatch.h"
 #include "base/string.h"
diff --git a/src/app/widget_not_found.h b/src/app/widget_not_found.h
index 351764ebd..c7ef2f66e 100644
--- a/src/app/widget_not_found.h
+++ b/src/app/widget_not_found.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_WIDGET_NOT_FOUND_H_INCLUDED
 #define APP_WIDGET_NOT_FOUND_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <stdexcept>
diff --git a/src/app/widget_type_mismatch.h b/src/app/widget_type_mismatch.h
index 0af544aee..287d21c26 100644
--- a/src/app/widget_type_mismatch.h
+++ b/src/app/widget_type_mismatch.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_WIDGET_TYPE_MISMATCH_H_INCLUDED
 #define APP_WIDGET_TYPE_MISMATCH_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <stdexcept>
diff --git a/src/app/xml_document.h b/src/app/xml_document.h
index 514fd3b41..8a598ffef 100644
--- a/src/app/xml_document.h
+++ b/src/app/xml_document.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_XML_DOCUMENT_H_INCLUDED
 #define APP_XML_DOCUMENT_H_INCLUDED
+#pragma once
 
 #include "base/exception.h"
 #include "base/shared_ptr.h"
diff --git a/src/app/xml_exception.h b/src/app/xml_exception.h
index b5da02659..6d225a3fa 100644
--- a/src/app/xml_exception.h
+++ b/src/app/xml_exception.h
@@ -18,6 +18,7 @@
 
 #ifndef APP_XML_EXCEPTION_H_INCLUDED
 #define APP_XML_EXCEPTION_H_INCLUDED
+#pragma once
 
 #include "base/exception.h"
 
diff --git a/src/base/bind.h b/src/base/bind.h
index 52346b417..652a3911b 100644
--- a/src/base/bind.h
+++ b/src/base/bind.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_BIND_H_INCLUDED
 #define BASE_BIND_H_INCLUDED
+#pragma once
 
 // BindAdapter0_fun
 template<typename R, typename F>
diff --git a/src/base/cfile.h b/src/base/cfile.h
index 2f8d6ef93..5a83677a7 100644
--- a/src/base/cfile.h
+++ b/src/base/cfile.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_CFILE_H_INCLUDED
 #define BASE_CFILE_H_INCLUDED
+#pragma once
 
 #include <cstdio>
 
diff --git a/src/base/chrono.h b/src/base/chrono.h
index 57e824a60..64730807f 100644
--- a/src/base/chrono.h
+++ b/src/base/chrono.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_CHRONO_H_INCLUDED
 #define BASE_CHRONO_H_INCLUDED
+#pragma once
 
 namespace base {
 
diff --git a/src/base/clamp.h b/src/base/clamp.h
index 603d7818c..3a3c77a3a 100644
--- a/src/base/clamp.h
+++ b/src/base/clamp.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_CLAMP_H_INCLUDED
 #define BASE_CLAMP_H_INCLUDED
+#pragma once
 
 namespace base {
 
diff --git a/src/base/compiler_specific.h b/src/base/compiler_specific.h
index a91bc0ecb..fc755cd42 100644
--- a/src/base/compiler_specific.h
+++ b/src/base/compiler_specific.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_COMPILER_SPECIFIC_H_INCLUDED
 #define BASE_COMPILER_SPECIFIC_H_INCLUDED
+#pragma once
 
 #ifdef _MSC_VER
   #define OVERRIDE override
diff --git a/src/base/convert_to.h b/src/base/convert_to.h
index ef7771bbe..1bde30aec 100644
--- a/src/base/convert_to.h
+++ b/src/base/convert_to.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_CONVERT_TO_H_INCLUDED
 #define BASE_CONVERT_TO_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 
diff --git a/src/base/disable_copying.h b/src/base/disable_copying.h
index 4bc3968c1..fd9ea1bde 100644
--- a/src/base/disable_copying.h
+++ b/src/base/disable_copying.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_DISABLE_COPYING_H_INCLUDED
 #define BASE_DISABLE_COPYING_H_INCLUDED
+#pragma once
 
 #define DISABLE_COPYING(ClassName)              \
   private:                                      \
diff --git a/src/base/errno_string.h b/src/base/errno_string.h
index aa893fd30..63cc0c405 100644
--- a/src/base/errno_string.h
+++ b/src/base/errno_string.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_ERRNO_STRING_H_INCLUDED
 #define BASE_ERRNO_STRING_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/base/exception.h b/src/base/exception.h
index c4c840d70..2f1be2053 100644
--- a/src/base/exception.h
+++ b/src/base/exception.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_EXCEPTION_H_INCLUDED
 #define BASE_EXCEPTION_H_INCLUDED
+#pragma once
 
 #include <exception>
 #include <string>
diff --git a/src/base/file_handle.h b/src/base/file_handle.h
index 17387884e..0cec8d62e 100644
--- a/src/base/file_handle.h
+++ b/src/base/file_handle.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_OPEN_FILE_H_INCLUDED
 #define BASE_OPEN_FILE_H_INCLUDED
+#pragma once
 
 #include "base/shared_ptr.h"
 #include "base/string.h"
diff --git a/src/base/fs.h b/src/base/fs.h
index 64c985fc7..d61c37ae9 100644
--- a/src/base/fs.h
+++ b/src/base/fs.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_FS_H_INCLUDED
 #define BASE_FS_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 
diff --git a/src/base/launcher.h b/src/base/launcher.h
index be54dd111..c3c003fce 100644
--- a/src/base/launcher.h
+++ b/src/base/launcher.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_LAUNCHER_H_INCLUDED
 #define BASE_LAUNCHER_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/base/mem_utils.h b/src/base/mem_utils.h
index 3d231fd91..34d4e578a 100644
--- a/src/base/mem_utils.h
+++ b/src/base/mem_utils.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_MEM_UTILS_H_INCLUDED
 #define BASE_MEM_UTILS_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/base/memory.h b/src/base/memory.h
index 6a561685d..e26a6ff37 100644
--- a/src/base/memory.h
+++ b/src/base/memory.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_MEMORY_H_INCLUDED
 #define BASE_MEMORY_H_INCLUDED
+#pragma once
 
 void* base_malloc (size_t bytes);
 void* base_malloc0(size_t bytes);
diff --git a/src/base/memory_dump.h b/src/base/memory_dump.h
index ee7aeb176..5a893a2ed 100644
--- a/src/base/memory_dump.h
+++ b/src/base/memory_dump.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_MEMORY_DUMP_H_INCLUDED
 #define BASE_MEMORY_DUMP_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/base/memory_dump_none.h b/src/base/memory_dump_none.h
index cfd7edcdc..421ad8059 100644
--- a/src/base/memory_dump_none.h
+++ b/src/base/memory_dump_none.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_MEMORY_DUMP_NONE_H_INCLUDED
 #define BASE_MEMORY_DUMP_NONE_H_INCLUDED
+#pragma once
 
 class base::MemoryDump::MemoryDumpImpl
 {
diff --git a/src/base/memory_dump_win32.h b/src/base/memory_dump_win32.h
index 656e51831..435d38a86 100644
--- a/src/base/memory_dump_win32.h
+++ b/src/base/memory_dump_win32.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_MEMORY_DUMP_WIN32_H_INCLUDED
 #define BASE_MEMORY_DUMP_WIN32_H_INCLUDED
+#pragma once
 
 #ifdef WIN32
 #include <windows.h>
diff --git a/src/base/mutex.h b/src/base/mutex.h
index 2fe406f19..6a41bb8b2 100644
--- a/src/base/mutex.h
+++ b/src/base/mutex.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_MUTEX_H_INCLUDED
 #define BASE_MUTEX_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 
diff --git a/src/base/mutex_pthread.h b/src/base/mutex_pthread.h
index 4a1da0709..4b22988bd 100644
--- a/src/base/mutex_pthread.h
+++ b/src/base/mutex_pthread.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_MUTEX_PTHREAD_H_INCLUDED
 #define BASE_MUTEX_PTHREAD_H_INCLUDED
+#pragma once
 
 #include <pthread.h>
 #include <errno.h>
diff --git a/src/base/mutex_win32.h b/src/base/mutex_win32.h
index cac90e256..21fb3aabb 100644
--- a/src/base/mutex_win32.h
+++ b/src/base/mutex_win32.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_MUTEX_WIN32_H_INCLUDED
 #define BASE_MUTEX_WIN32_H_INCLUDED
+#pragma once
 
 #include <windows.h>
 
diff --git a/src/base/observable.h b/src/base/observable.h
index 641aaf195..30c75a7e8 100644
--- a/src/base/observable.h
+++ b/src/base/observable.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_OBSERVABLE_H_INCLUDED
 #define BASE_OBSERVABLE_H_INCLUDED
+#pragma once
 
 #include "base/observers.h"
 
diff --git a/src/base/observers.h b/src/base/observers.h
index c0b7d884b..57a151389 100644
--- a/src/base/observers.h
+++ b/src/base/observers.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_OBSERVERS_H_INCLUDED
 #define BASE_OBSERVERS_H_INCLUDED
+#pragma once
 
 #include <algorithm>
 #include <vector>
diff --git a/src/base/path.h b/src/base/path.h
index 01669c1bc..0531b1259 100644
--- a/src/base/path.h
+++ b/src/base/path.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_PATH_H_INCLUDED
 #define BASE_PATH_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 
diff --git a/src/base/program_options.h b/src/base/program_options.h
index f5b05faec..0990e9084 100644
--- a/src/base/program_options.h
+++ b/src/base/program_options.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_PROGRAM_OPTIONS_H_INCLUDED
 #define BASE_PROGRAM_OPTIONS_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <vector>
diff --git a/src/base/recent_items.h b/src/base/recent_items.h
index ba22ac113..f2f45e797 100644
--- a/src/base/recent_items.h
+++ b/src/base/recent_items.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_RECENT_ITEMS_H_INCLUDED
 #define BASE_RECENT_ITEMS_H_INCLUDED
+#pragma once
 
 #include <list>
 #include <algorithm>
diff --git a/src/base/remove_from_container.h b/src/base/remove_from_container.h
index 4b3ae6a22..b218fe394 100644
--- a/src/base/remove_from_container.h
+++ b/src/base/remove_from_container.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_REMOVE_FROM_CONTAINER_H_INCLUDED
 #define BASE_REMOVE_FROM_CONTAINER_H_INCLUDED
+#pragma once
 
 namespace base {
 
diff --git a/src/base/scoped_lock.h b/src/base/scoped_lock.h
index 12f7877ec..716b71c64 100644
--- a/src/base/scoped_lock.h
+++ b/src/base/scoped_lock.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_SCOPED_LOCK_H_INCLUDED
 #define BASE_SCOPED_LOCK_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 
diff --git a/src/base/serialization.h b/src/base/serialization.h
index aa3fc3855..5c195757e 100644
--- a/src/base/serialization.h
+++ b/src/base/serialization.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_SERIALIZATION_H_INCLUDED
 #define BASE_SERIALIZATION_H_INCLUDED
+#pragma once
 
 #include <iosfwd>
 
diff --git a/src/base/sha1.h b/src/base/sha1.h
index 5c3f75b5b..518184f31 100644
--- a/src/base/sha1.h
+++ b/src/base/sha1.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_SHA1_H_INCLUDED
 #define BASE_SHA1_H_INCLUDED
+#pragma once
 
 #include <vector>
 #include <string>
diff --git a/src/base/sha1_rfc3174.h b/src/base/sha1_rfc3174.h
index 9b3e539e2..adb8393c5 100644
--- a/src/base/sha1_rfc3174.h
+++ b/src/base/sha1_rfc3174.h
@@ -16,6 +16,7 @@
 
 #ifndef BASE_SHA1_RFC3174_H_INCLUDED
 #define BASE_SHA1_RFC3174_H_INCLUDED
+#pragma once
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/base/shared_ptr.h b/src/base/shared_ptr.h
index ad02de5d5..d2c00fd9d 100644
--- a/src/base/shared_ptr.h
+++ b/src/base/shared_ptr.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_SHARED_PTR_H_INCLUDED
 #define BASE_SHARED_PTR_H_INCLUDED
+#pragma once
 
 // This class counts references for a SharedPtr.
 class SharedPtrRefCounterBase
diff --git a/src/base/signal.h b/src/base/signal.h
index 08ecc21c9..907bf97e4 100644
--- a/src/base/signal.h
+++ b/src/base/signal.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_SIGNAL_H_INCLUDED
 #define BASE_SIGNAL_H_INCLUDED
+#pragma once
 
 #include "base/slot.h"
 #include "base/remove_from_container.h"
diff --git a/src/base/slot.h b/src/base/slot.h
index 16a303528..5604469e0 100644
--- a/src/base/slot.h
+++ b/src/base/slot.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_SLOT_H_INCLUDED
 #define BASE_SLOT_H_INCLUDED
+#pragma once
 
 // Slot0 - Base class for delegates of zero arguments.
 template<typename R>
diff --git a/src/base/split_string.h b/src/base/split_string.h
index 52d75a313..cde2f76ce 100644
--- a/src/base/split_string.h
+++ b/src/base/split_string.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_SPLIT_STRING_H_INCLUDED
 #define BASE_SPLIT_STRING_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 #include <vector>
diff --git a/src/base/string.h b/src/base/string.h
index 107c0fd3e..970ef41c2 100644
--- a/src/base/string.h
+++ b/src/base/string.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_STRING_H_INCLUDED
 #define BASE_STRING_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <iterator>
diff --git a/src/base/system_console.h b/src/base/system_console.h
index 6bfbe5bdf..9a8488e5f 100644
--- a/src/base/system_console.h
+++ b/src/base/system_console.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_SYSTEM_CONSOLE_H_INCLUDED
 #define BASE_SYSTEM_CONSOLE_H_INCLUDED
+#pragma once
 
 namespace base {
 
diff --git a/src/base/temp_dir.h b/src/base/temp_dir.h
index c91b65673..802d5e27a 100644
--- a/src/base/temp_dir.h
+++ b/src/base/temp_dir.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_TEMP_DIR_H_INCLUDED
 #define BASE_TEMP_DIR_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 
diff --git a/src/base/thread.h b/src/base/thread.h
index 44b69bf0e..32af77d14 100644
--- a/src/base/thread.h
+++ b/src/base/thread.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_THREAD_H_INCLUDED
 #define BASE_THREAD_H_INCLUDED
+#pragma once
 
 namespace base {                // Based on C++0x threads lib
 
diff --git a/src/base/trim_string.h b/src/base/trim_string.h
index 9a97b4446..4bf07b679 100644
--- a/src/base/trim_string.h
+++ b/src/base/trim_string.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_TRIM_STRING_H_INCLUDED
 #define BASE_TRIM_STRING_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 
diff --git a/src/base/unique_ptr.h b/src/base/unique_ptr.h
index 6a675e803..01f88e1ac 100644
--- a/src/base/unique_ptr.h
+++ b/src/base/unique_ptr.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_UNIQUE_PTR_H_INCLUDED
 #define BASE_UNIQUE_PTR_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 
diff --git a/src/base/vector2d.h b/src/base/vector2d.h
index 0c0c60dfb..66b3acc96 100644
--- a/src/base/vector2d.h
+++ b/src/base/vector2d.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_VECTOR2D_H_INCLUDED
 #define BASE_VECTOR2D_H_INCLUDED
+#pragma once
 
 #include <cmath>
 
diff --git a/src/base/version.h b/src/base/version.h
index e0978bc93..0d898b8fd 100644
--- a/src/base/version.h
+++ b/src/base/version.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_VERSION_H_INCLUDED
 #define BASE_VERSION_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <vector>
diff --git a/src/base/win32_exception.h b/src/base/win32_exception.h
index 8731282ec..7a348f110 100644
--- a/src/base/win32_exception.h
+++ b/src/base/win32_exception.h
@@ -6,6 +6,7 @@
 
 #ifndef BASE_WIN32_EXCEPTION_H_INCLUDED
 #define BASE_WIN32_EXCEPTION_H_INCLUDED
+#pragma once
 
 #include "exception.h"
 
diff --git a/src/css/compound_style.h b/src/css/compound_style.h
index d9e106b72..706b3aaf0 100644
--- a/src/css/compound_style.h
+++ b/src/css/compound_style.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_COMPOUND_STYLE_H_INCLUDED
 #define CSS_COMPOUND_STYLE_H_INCLUDED
+#pragma once
 
 #include "css/query.h"
 #include "css/rule.h"
diff --git a/src/css/css.h b/src/css/css.h
index 9e9f4ea85..492d1d95e 100644
--- a/src/css/css.h
+++ b/src/css/css.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_CSS_H_INCLUDED
 #define CSS_CSS_H_INCLUDED
+#pragma once
 
 #include "css/compound_style.h"
 #include "css/query.h"
diff --git a/src/css/map.h b/src/css/map.h
index a5e6e8d37..75189bf3f 100644
--- a/src/css/map.h
+++ b/src/css/map.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_MAP_H_INCLUDED
 #define CSS_MAP_H_INCLUDED
+#pragma once
 
 #include <map>
 #include <string>
diff --git a/src/css/query.h b/src/css/query.h
index 47f1ae97e..6a1f2d639 100644
--- a/src/css/query.h
+++ b/src/css/query.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_QUERY_H_INCLUDED
 #define CSS_QUERY_H_INCLUDED
+#pragma once
 
 #include "css/rule.h"
 #include "css/style.h"
diff --git a/src/css/rule.h b/src/css/rule.h
index 2e13852e5..70d3e9bb9 100644
--- a/src/css/rule.h
+++ b/src/css/rule.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_RULE_H_INCLUDED
 #define CSS_RULE_H_INCLUDED
+#pragma once
 
 #include "css/map.h"
 
diff --git a/src/css/sheet.h b/src/css/sheet.h
index c6fad8ec9..8dac7243f 100644
--- a/src/css/sheet.h
+++ b/src/css/sheet.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_SHEET_H_INCLUDED
 #define CSS_SHEET_H_INCLUDED
+#pragma once
 
 #include "css/rule.h"
 #include "css/style.h"
diff --git a/src/css/state.h b/src/css/state.h
index f93bc4d22..4f95c0c86 100644
--- a/src/css/state.h
+++ b/src/css/state.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_STATE_H_INCLUDED
 #define CSS_STATE_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <vector>
diff --git a/src/css/stateful_style.h b/src/css/stateful_style.h
index 51d7db6d6..ac21a32be 100644
--- a/src/css/stateful_style.h
+++ b/src/css/stateful_style.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_STATEFUL_STYLE_H_INCLUDED
 #define CSS_STATEFUL_STYLE_H_INCLUDED
+#pragma once
 
 #include "css/rule.h"
 #include "css/state.h"
diff --git a/src/css/style.h b/src/css/style.h
index add9710e5..34562aabd 100644
--- a/src/css/style.h
+++ b/src/css/style.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_STYLE_H_INCLUDED
 #define CSS_STYLE_H_INCLUDED
+#pragma once
 
 #include <map>
 #include <string>
diff --git a/src/css/value.h b/src/css/value.h
index 194d69dfd..be50f05d0 100644
--- a/src/css/value.h
+++ b/src/css/value.h
@@ -6,6 +6,7 @@
 
 #ifndef CSS_VALUE_H_INCLUDED
 #define CSS_VALUE_H_INCLUDED
+#pragma once
 
 #include "css/map.h"
 
diff --git a/src/doc/document.h b/src/doc/document.h
index fe64cbe50..71129910c 100644
--- a/src/doc/document.h
+++ b/src/doc/document.h
@@ -6,6 +6,7 @@
 
 #ifndef DOC_DOCUMENT_H_INCLUDED
 #define DOC_DOCUMENT_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/doc/export_data.h b/src/doc/export_data.h
index 79eb1f3f4..b6421cb24 100644
--- a/src/doc/export_data.h
+++ b/src/doc/export_data.h
@@ -6,6 +6,7 @@
 
 #ifndef DOC_EXPORT_DATA_H_INCLUDED
 #define DOC_EXPORT_DATA_H_INCLUDED
+#pragma once
 
 #include "base/shared_ptr.h"
 #include "gfx/rect.h"
diff --git a/src/doc/object.h b/src/doc/object.h
index c0ae375c0..5d5d80d98 100644
--- a/src/doc/object.h
+++ b/src/doc/object.h
@@ -6,6 +6,7 @@
 
 #ifndef DOC_OBJECT_H_INCLUDED
 #define DOC_OBJECT_H_INCLUDED
+#pragma once
 
 #include "doc/object_id.h"
 
diff --git a/src/doc/object_id.h b/src/doc/object_id.h
index 9c5565cf4..fc6123fa6 100644
--- a/src/doc/object_id.h
+++ b/src/doc/object_id.h
@@ -6,6 +6,7 @@
 
 #ifndef DOC_OBJECT_ID_H_INCLUDED
 #define DOC_OBJECT_ID_H_INCLUDED
+#pragma once
 
 namespace doc {
 
diff --git a/src/filters/color_curve.h b/src/filters/color_curve.h
index 30035427e..eecab40df 100644
--- a/src/filters/color_curve.h
+++ b/src/filters/color_curve.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_COLOR_CURVE_H_INCLUDED
 #define FILTERS_COLOR_CURVE_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/filters/color_curve_filter.h b/src/filters/color_curve_filter.h
index 22b9b7dc9..2568561e8 100644
--- a/src/filters/color_curve_filter.h
+++ b/src/filters/color_curve_filter.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_COLOR_CURVE_FILTER_H_INCLUDED
 #define FILTERS_COLOR_CURVE_FILTER_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/filters/convolution_matrix.h b/src/filters/convolution_matrix.h
index a099f829c..7dd009700 100644
--- a/src/filters/convolution_matrix.h
+++ b/src/filters/convolution_matrix.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_CONVOLUTION_MATRIX_H_INCLUDED
 #define FILTERS_CONVOLUTION_MATRIX_H_INCLUDED
+#pragma once
 
 #include "filters/target.h"
 
diff --git a/src/filters/convolution_matrix_filter.h b/src/filters/convolution_matrix_filter.h
index 8dc41b950..44117caaa 100644
--- a/src/filters/convolution_matrix_filter.h
+++ b/src/filters/convolution_matrix_filter.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_CONVOLUTION_MATRIX_FILTER_H_INCLUDED
 #define FILTERS_CONVOLUTION_MATRIX_FILTER_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/filters/filter.h b/src/filters/filter.h
index aeb0ff6f4..73849519c 100644
--- a/src/filters/filter.h
+++ b/src/filters/filter.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_FILTER_H_INCLUDED
 #define FILTERS_FILTER_H_INCLUDED
+#pragma once
 
 namespace filters {
 
diff --git a/src/filters/filter_indexed_data.h b/src/filters/filter_indexed_data.h
index 804c6599d..55f9f825e 100644
--- a/src/filters/filter_indexed_data.h
+++ b/src/filters/filter_indexed_data.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_FILTER_INDEXED_DATA_H_INCLUDED
 #define FILTERS_FILTER_INDEXED_DATA_H_INCLUDED
+#pragma once
 
 namespace raster {
   class Palette;
diff --git a/src/filters/filter_manager.h b/src/filters/filter_manager.h
index cea180ceb..8afa43cf2 100644
--- a/src/filters/filter_manager.h
+++ b/src/filters/filter_manager.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_FILTER_MANAGER_H_INCLUDED
 #define FILTERS_FILTER_MANAGER_H_INCLUDED
+#pragma once
 
 #include "filters/target.h"
 
diff --git a/src/filters/invert_color_filter.h b/src/filters/invert_color_filter.h
index d12487565..4517e21bd 100644
--- a/src/filters/invert_color_filter.h
+++ b/src/filters/invert_color_filter.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_INVERT_COLOR_FILTER_H_INCLUDED
 #define FILTERS_INVERT_COLOR_FILTER_H_INCLUDED
+#pragma once
 
 #include "filters/filter.h"
 
diff --git a/src/filters/median_filter.h b/src/filters/median_filter.h
index 7f3d48799..2309a2a54 100644
--- a/src/filters/median_filter.h
+++ b/src/filters/median_filter.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_MEDIAN_FILTER_PROCESS_H_INCLUDED
 #define FILTERS_MEDIAN_FILTER_PROCESS_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/filters/neighboring_pixels.h b/src/filters/neighboring_pixels.h
index c13109816..dc66c22ba 100644
--- a/src/filters/neighboring_pixels.h
+++ b/src/filters/neighboring_pixels.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_NEIGHBORING_PIXELS_H_INCLUDED
 #define FILTERS_NEIGHBORING_PIXELS_H_INCLUDED
+#pragma once
 
 #include "filters/tiled_mode.h"
 #include "raster/image.h"
diff --git a/src/filters/replace_color_filter.h b/src/filters/replace_color_filter.h
index 341a7297a..7772d0f2c 100644
--- a/src/filters/replace_color_filter.h
+++ b/src/filters/replace_color_filter.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_REPLACE_COLOR_FILTER_H_INCLUDED
 #define FILTERS_REPLACE_COLOR_FILTER_H_INCLUDED
+#pragma once
 
 #include "filters/filter.h"
 
diff --git a/src/filters/target.h b/src/filters/target.h
index 2f19e03a1..442a4acba 100644
--- a/src/filters/target.h
+++ b/src/filters/target.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_TARGET_H_INCLUDED
 #define FILTERS_TARGET_H_INCLUDED
+#pragma once
 
 #define TARGET_RED_CHANNEL              1
 #define TARGET_GREEN_CHANNEL            2
diff --git a/src/filters/tiled_mode.h b/src/filters/tiled_mode.h
index f26d6f8ee..bb58100cf 100644
--- a/src/filters/tiled_mode.h
+++ b/src/filters/tiled_mode.h
@@ -18,6 +18,7 @@
 
 #ifndef FILTERS_TILED_MODE_H_INCLUDED
 #define FILTERS_TILED_MODE_H_INCLUDED
+#pragma once
 
 namespace filters {
 
diff --git a/src/gfx/border.h b/src/gfx/border.h
index 8ed1e5c85..4fd9d9325 100644
--- a/src/gfx/border.h
+++ b/src/gfx/border.h
@@ -6,6 +6,7 @@
 
 #ifndef GFX_BORDER_H_INCLUDED
 #define GFX_BORDER_H_INCLUDED
+#pragma once
 
 namespace gfx {
 
diff --git a/src/gfx/fwd.h b/src/gfx/fwd.h
index f6d837628..add2ddda8 100644
--- a/src/gfx/fwd.h
+++ b/src/gfx/fwd.h
@@ -6,6 +6,7 @@
 
 #ifndef GFX_FWD_H_INCLUDED
 #define GFX_FWD_H_INCLUDED
+#pragma once
 
 namespace gfx {
 
diff --git a/src/gfx/hsv.h b/src/gfx/hsv.h
index e3c377073..50ade6c39 100644
--- a/src/gfx/hsv.h
+++ b/src/gfx/hsv.h
@@ -6,6 +6,7 @@
 
 #ifndef GFX_HSV_H_INCLUDED
 #define GFX_HSV_H_INCLUDED
+#pragma once
 
 #include <cassert>
 
diff --git a/src/gfx/point.h b/src/gfx/point.h
index d9bb79e72..2c198d71e 100644
--- a/src/gfx/point.h
+++ b/src/gfx/point.h
@@ -6,6 +6,7 @@
 
 #ifndef GFX_POINT_H_INCLUDED
 #define GFX_POINT_H_INCLUDED
+#pragma once
 
 namespace gfx {
 
diff --git a/src/gfx/rect.h b/src/gfx/rect.h
index e0bde8491..fc8b15eb6 100644
--- a/src/gfx/rect.h
+++ b/src/gfx/rect.h
@@ -6,6 +6,7 @@
 
 #ifndef GFX_RECT_H_INCLUDED
 #define GFX_RECT_H_INCLUDED
+#pragma once
 
 namespace gfx {
 
diff --git a/src/gfx/region.h b/src/gfx/region.h
index 97d9c1701..c692e9be9 100644
--- a/src/gfx/region.h
+++ b/src/gfx/region.h
@@ -6,6 +6,7 @@
 
 #ifndef GFX_REGION_H_INCLUDED
 #define GFX_REGION_H_INCLUDED
+#pragma once
 
 #include "gfx/rect.h"
 #include <vector>
diff --git a/src/gfx/rgb.h b/src/gfx/rgb.h
index 0fdc99040..68f41f552 100644
--- a/src/gfx/rgb.h
+++ b/src/gfx/rgb.h
@@ -6,6 +6,7 @@
 
 #ifndef GFX_RGB_H_INCLUDED
 #define GFX_RGB_H_INCLUDED
+#pragma once
 
 #include <cassert>
 
diff --git a/src/gfx/size.h b/src/gfx/size.h
index a756eb7cc..e425d04d8 100644
--- a/src/gfx/size.h
+++ b/src/gfx/size.h
@@ -6,6 +6,7 @@
 
 #ifndef GFX_SIZE_H_INCLUDED
 #define GFX_SIZE_H_INCLUDED
+#pragma once
 
 #include <algorithm>
 
diff --git a/src/gfx/transformation.h b/src/gfx/transformation.h
index 5c654825c..109713d3b 100644
--- a/src/gfx/transformation.h
+++ b/src/gfx/transformation.h
@@ -6,6 +6,7 @@
 
 #ifndef TRANSFORMATION_H_INCLUDED
 #define TRANSFORMATION_H_INCLUDED
+#pragma once
 
 #include "gfx/point.h"
 #include "gfx/rect.h"
diff --git a/src/net/http_headers.h b/src/net/http_headers.h
index 6f2c263e7..4cd19f9eb 100644
--- a/src/net/http_headers.h
+++ b/src/net/http_headers.h
@@ -18,6 +18,7 @@
 
 #ifndef NET_HTTP_HEADERS_H_INCLUDED
 #define NET_HTTP_HEADERS_H_INCLUDED
+#pragma once
 
 #include <map>
 #include <string>
diff --git a/src/net/http_request.h b/src/net/http_request.h
index 2e6babd47..9f2065bf6 100644
--- a/src/net/http_request.h
+++ b/src/net/http_request.h
@@ -18,6 +18,7 @@
 
 #ifndef NET_HTTP_REQUEST_H_INCLUDED
 #define NET_HTTP_REQUEST_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 
diff --git a/src/net/http_response.h b/src/net/http_response.h
index 27a07dff6..9afc73155 100644
--- a/src/net/http_response.h
+++ b/src/net/http_response.h
@@ -18,6 +18,7 @@
 
 #ifndef NET_HTTP_RESPONSE_H_INCLUDED
 #define NET_HTTP_RESPONSE_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 
diff --git a/src/raster/algo.h b/src/raster/algo.h
index d6f1b6b72..4eaca8764 100644
--- a/src/raster/algo.h
+++ b/src/raster/algo.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_ALGO_H_INCLUDED
 #define RASTER_ALGO_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/algorithm/flip_image.h b/src/raster/algorithm/flip_image.h
index 1db43767e..003ec8ae9 100644
--- a/src/raster/algorithm/flip_image.h
+++ b/src/raster/algorithm/flip_image.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_ALGORITHM_FLIP_IMAGE_H_INCLUDED
 #define RASTER_ALGORITHM_FLIP_IMAGE_H_INCLUDED
+#pragma once
 
 #include "gfx/fwd.h"
 #include "raster/algorithm/flip_type.h"
diff --git a/src/raster/algorithm/flip_type.h b/src/raster/algorithm/flip_type.h
index ab1e71e09..7e434a78f 100644
--- a/src/raster/algorithm/flip_type.h
+++ b/src/raster/algorithm/flip_type.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_ALGORITHM_FLIP_TYPE_H_INCLUDED
 #define RASTER_ALGORITHM_FLIP_TYPE_H_INCLUDED
+#pragma once
 
 namespace raster {
   namespace algorithm {
diff --git a/src/raster/algorithm/resize_image.h b/src/raster/algorithm/resize_image.h
index 992798cdb..551eb1900 100644
--- a/src/raster/algorithm/resize_image.h
+++ b/src/raster/algorithm/resize_image.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_ALGORITHM_RESIZE_IMAGE_H_INCLUDED
 #define RASTER_ALGORITHM_RESIZE_IMAGE_H_INCLUDED
+#pragma once
 
 #include "gfx/fwd.h"
 
diff --git a/src/raster/algorithm/shrink_bounds.h b/src/raster/algorithm/shrink_bounds.h
index d1f648022..7e0afaf15 100644
--- a/src/raster/algorithm/shrink_bounds.h
+++ b/src/raster/algorithm/shrink_bounds.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_ALGORITHM_SHRINK_BOUNDS_H_INCLUDED
 #define RASTER_ALGORITHM_SHRINK_BOUNDS_H_INCLUDED
+#pragma once
 
 #include "gfx/fwd.h"
 #include "raster/algorithm/flip_type.h"
diff --git a/src/raster/blend.h b/src/raster/blend.h
index 4ca1a24df..b4bfcbb4e 100644
--- a/src/raster/blend.h
+++ b/src/raster/blend.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_BLEND_H_INCLUDED
 #define RASTER_BLEND_H_INCLUDED
+#pragma once
 
 #define INT_MULT(a, b, t)                               \
   ((t) = (a) * (b) + 0x80, ((((t) >> 8) + (t)) >> 8))
diff --git a/src/raster/cel.h b/src/raster/cel.h
index a2ad4a529..9e28f4cd6 100644
--- a/src/raster/cel.h
+++ b/src/raster/cel.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_CEL_H_INCLUDED
 #define RASTER_CEL_H_INCLUDED
+#pragma once
 
 #include "raster/frame_number.h"
 #include "raster/object.h"
diff --git a/src/raster/cel_io.h b/src/raster/cel_io.h
index dcce2c7e0..3c4c80cda 100644
--- a/src/raster/cel_io.h
+++ b/src/raster/cel_io.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_CEL_IO_H_INCLUDED
 #define RASTER_CEL_IO_H_INCLUDED
+#pragma once
 
 #include <iosfwd>
 
diff --git a/src/raster/color.h b/src/raster/color.h
index 6b77fa450..63c425ebc 100644
--- a/src/raster/color.h
+++ b/src/raster/color.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_COLOR_H_INCLUDED
 #define RASTER_COLOR_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/color_histogram.h b/src/raster/color_histogram.h
index 114f366e0..c1e8a15f6 100644
--- a/src/raster/color_histogram.h
+++ b/src/raster/color_histogram.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_COLOR_HISTOGRAM_H_INCLUDED
 #define RASTER_COLOR_HISTOGRAM_H_INCLUDED
+#pragma once
 
 #include <limits>
 #include <vector>
diff --git a/src/raster/color_scales.h b/src/raster/color_scales.h
index 31a2dbf7a..ee4a62628 100644
--- a/src/raster/color_scales.h
+++ b/src/raster/color_scales.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_COLOR_SCALES_H_INCLUDED
 #define RASTER_COLOR_SCALES_H_INCLUDED
+#pragma once
 
 #include "raster/frame_number.h"
 #include "raster/object.h"
diff --git a/src/raster/conversion_alleg.h b/src/raster/conversion_alleg.h
index 22e419a81..cad42a548 100644
--- a/src/raster/conversion_alleg.h
+++ b/src/raster/conversion_alleg.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_CONVERSION_ALLEG_H_INCLUDED
 #define RASTER_CONVERSION_ALLEG_H_INCLUDED
+#pragma once
 
 #include <allegro/color.h>
 
diff --git a/src/raster/dirty.h b/src/raster/dirty.h
index f9091a861..4ab560024 100644
--- a/src/raster/dirty.h
+++ b/src/raster/dirty.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_DIRTY_H_INCLUDED
 #define RASTER_DIRTY_H_INCLUDED
+#pragma once
 
 #include "raster/image.h"
 
diff --git a/src/raster/dirty_io.h b/src/raster/dirty_io.h
index 0b4b5e6e0..9376880ec 100644
--- a/src/raster/dirty_io.h
+++ b/src/raster/dirty_io.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_DIRTY_IO_H_INCLUDED
 #define RASTER_DIRTY_IO_H_INCLUDED
+#pragma once
 
 #include <iosfwd>
 
diff --git a/src/raster/dithering_method.h b/src/raster/dithering_method.h
index 1a5ad924b..81a052c4c 100644
--- a/src/raster/dithering_method.h
+++ b/src/raster/dithering_method.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_DITHERING_METHOD_H_INCLUDED
 #define RASTER_DITHERING_METHOD_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/file/col_file.h b/src/raster/file/col_file.h
index 0951bfb73..4bc59eaa3 100644
--- a/src/raster/file/col_file.h
+++ b/src/raster/file/col_file.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_FILE_COL_FILE_H_INCLUDED
 #define RASTER_FILE_COL_FILE_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/file/gpl_file.h b/src/raster/file/gpl_file.h
index fb287f5fd..ac60f9c56 100644
--- a/src/raster/file/gpl_file.h
+++ b/src/raster/file/gpl_file.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_FILE_GPL_FILE_H_INCLUDED
 #define RASTER_FILE_GPL_FILE_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/frame_number.h b/src/raster/frame_number.h
index 7304a0d1e..00360deda 100644
--- a/src/raster/frame_number.h
+++ b/src/raster/frame_number.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_FRAME_NUMBER_H_INCLUDED
 #define RASTER_FRAME_NUMBER_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/image.h b/src/raster/image.h
index 95e65b6b3..a8d288187 100644
--- a/src/raster/image.h
+++ b/src/raster/image.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_IMAGE_H_INCLUDED
 #define RASTER_IMAGE_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "gfx/rect.h"
diff --git a/src/raster/image_bits.h b/src/raster/image_bits.h
index 04c7feecc..02da62fdd 100644
--- a/src/raster/image_bits.h
+++ b/src/raster/image_bits.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_IMAGE_BITS_H_INCLUDED
 #define RASTER_IMAGE_BITS_H_INCLUDED
+#pragma once
 
 #include "raster/image.h"
 #include "raster/image_iterator.h"
diff --git a/src/raster/image_buffer.h b/src/raster/image_buffer.h
index 565ce680d..2013f5a21 100644
--- a/src/raster/image_buffer.h
+++ b/src/raster/image_buffer.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_IMAGE_BUFFER_H_INCLUDED
 #define RASTER_IMAGE_BUFFER_H_INCLUDED
+#pragma once
 
 #include "base/shared_ptr.h"
 
diff --git a/src/raster/image_impl.h b/src/raster/image_impl.h
index 4abe66319..24382aaf8 100644
--- a/src/raster/image_impl.h
+++ b/src/raster/image_impl.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_IMAGE_IMPL_H_INCLUDED
 #define RASTER_IMAGE_IMPL_H_INCLUDED
+#pragma once
 
 #include "raster/blend.h"
 #include "raster/image.h"
diff --git a/src/raster/image_io.h b/src/raster/image_io.h
index 136bcb937..e5b23b195 100644
--- a/src/raster/image_io.h
+++ b/src/raster/image_io.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_IMAGE_IO_H_INCLUDED
 #define RASTER_IMAGE_IO_H_INCLUDED
+#pragma once
 
 #include <iosfwd>
 
diff --git a/src/raster/image_iterator.h b/src/raster/image_iterator.h
index b083ab7b6..b7ea931a9 100644
--- a/src/raster/image_iterator.h
+++ b/src/raster/image_iterator.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_IMAGE_ITERATOR_H_INCLUDED
 #define RASTER_IMAGE_ITERATOR_H_INCLUDED
+#pragma once
 
 #include "gfx/point.h"
 #include "gfx/rect.h"
diff --git a/src/raster/image_traits.h b/src/raster/image_traits.h
index 8b8b2be6d..c8af60c7c 100644
--- a/src/raster/image_traits.h
+++ b/src/raster/image_traits.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_IMAGE_TRAITS_H_INCLUDED
 #define RASTER_IMAGE_TRAITS_H_INCLUDED
+#pragma once
 
 #include "raster/pixel_format.h"
 
diff --git a/src/raster/images_collector.h b/src/raster/images_collector.h
index e21a80dfc..5bdc49bef 100644
--- a/src/raster/images_collector.h
+++ b/src/raster/images_collector.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_IMAGES_REF_H_INCLUDED
 #define RASTER_IMAGES_REF_H_INCLUDED
+#pragma once
 
 #include "raster/frame_number.h"
 
diff --git a/src/raster/layer.h b/src/raster/layer.h
index ca3024d11..2a6ecedf4 100644
--- a/src/raster/layer.h
+++ b/src/raster/layer.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_LAYER_H_INCLUDED
 #define RASTER_LAYER_H_INCLUDED
+#pragma once
 
 #include "raster/blend.h"
 #include "raster/frame_number.h"
diff --git a/src/raster/layer_index.h b/src/raster/layer_index.h
index b0f3da0d3..e2cb03012 100644
--- a/src/raster/layer_index.h
+++ b/src/raster/layer_index.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_LAYER_INDEX_H_INCLUDED
 #define RASTER_LAYER_INDEX_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/layer_io.h b/src/raster/layer_io.h
index 0ff8a0997..148bf841e 100644
--- a/src/raster/layer_io.h
+++ b/src/raster/layer_io.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_LAYER_IO_H_INCLUDED
 #define RASTER_LAYER_IO_H_INCLUDED
+#pragma once
 
 #include "base/exception.h"
 
diff --git a/src/raster/mask.h b/src/raster/mask.h
index b92e2d047..68ec76c5d 100644
--- a/src/raster/mask.h
+++ b/src/raster/mask.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_MASK_H_INCLUDED
 #define RASTER_MASK_H_INCLUDED
+#pragma once
 
 #include "gfx/rect.h"
 #include "raster/image.h"
diff --git a/src/raster/mask_io.h b/src/raster/mask_io.h
index d0a900c4b..7ae805862 100644
--- a/src/raster/mask_io.h
+++ b/src/raster/mask_io.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_MASK_IO_H_INCLUDED
 #define RASTER_MASK_IO_H_INCLUDED
+#pragma once
 
 #include <iosfwd>
 
diff --git a/src/raster/median_cut.h b/src/raster/median_cut.h
index bf6b8b4a0..978a59262 100644
--- a/src/raster/median_cut.h
+++ b/src/raster/median_cut.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_MEDIAN_CUT_H_INCLUDED
 #define RASTER_MEDIAN_CUT_H_INCLUDED
+#pragma once
 
 #include <list>
 #include <queue>
diff --git a/src/raster/object.h b/src/raster/object.h
index 67d6c23f1..1d7e32e95 100644
--- a/src/raster/object.h
+++ b/src/raster/object.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_OBJECT_H_INCLUDED
 #define RASTER_OBJECT_H_INCLUDED
+#pragma once
 
 #include <list>
 
diff --git a/src/raster/palette.h b/src/raster/palette.h
index 3e34eced7..acf0c0465 100644
--- a/src/raster/palette.h
+++ b/src/raster/palette.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_PALETTE_H_INCLUDED
 #define RASTER_PALETTE_H_INCLUDED
+#pragma once
 
 #include "raster/color.h"
 #include "raster/frame_number.h"
diff --git a/src/raster/palette_io.h b/src/raster/palette_io.h
index 2a89a68d9..1db8d3bdd 100644
--- a/src/raster/palette_io.h
+++ b/src/raster/palette_io.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_PALETTE_IO_H_INCLUDED
 #define RASTER_PALETTE_IO_H_INCLUDED
+#pragma once
 
 #include <iosfwd>
 
diff --git a/src/raster/path.h b/src/raster/path.h
index 135027be9..e31e349bc 100644
--- a/src/raster/path.h
+++ b/src/raster/path.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_PATH_H_INCLUDED
 #define RASTER_PATH_H_INCLUDED
+#pragma once
 
 #error This file is deprecated
 
diff --git a/src/raster/pen.h b/src/raster/pen.h
index bff2913c6..26802bd26 100644
--- a/src/raster/pen.h
+++ b/src/raster/pen.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_PEN_H_INCLUDED
 #define RASTER_PEN_H_INCLUDED
+#pragma once
 
 #include "gfx/point.h"
 #include "gfx/rect.h"
diff --git a/src/raster/pen_type.h b/src/raster/pen_type.h
index d98297f86..030fef372 100644
--- a/src/raster/pen_type.h
+++ b/src/raster/pen_type.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_PEN_TYPE_H_INCLUDED
 #define RASTER_PEN_TYPE_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/pixel_format.h b/src/raster/pixel_format.h
index cc1bff01c..4a0cd9829 100644
--- a/src/raster/pixel_format.h
+++ b/src/raster/pixel_format.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_PIXEL_FORMAT_H_INCLUDED
 #define RASTER_PIXEL_FORMAT_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/primitives.h b/src/raster/primitives.h
index 09f13cff3..0eaa24516 100644
--- a/src/raster/primitives.h
+++ b/src/raster/primitives.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_PRIMITIVES_H_INCLUDED
 #define RASTER_PRIMITIVES_H_INCLUDED
+#pragma once
 
 #include "raster/color.h"
 #include "raster/image_buffer.h"
diff --git a/src/raster/primitives_fast.h b/src/raster/primitives_fast.h
index 2539c8681..597823fc0 100644
--- a/src/raster/primitives_fast.h
+++ b/src/raster/primitives_fast.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_PRIMITIVES_FAST_H_INCLUDED
 #define RASTER_PRIMITIVES_FAST_H_INCLUDED
+#pragma once
 
 #include "raster/color.h"
 #include "raster/image_impl.h"
diff --git a/src/raster/quantization.h b/src/raster/quantization.h
index b9a7beb25..f3aae6440 100644
--- a/src/raster/quantization.h
+++ b/src/raster/quantization.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_QUANTIZATION_H_INCLUDED
 #define RASTER_QUANTIZATION_H_INCLUDED
+#pragma once
 
 #include "raster/dithering_method.h"
 #include "raster/frame_number.h"
diff --git a/src/raster/raster.h b/src/raster/raster.h
index 69fdceac9..ff2e9f610 100644
--- a/src/raster/raster.h
+++ b/src/raster/raster.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_RASTER_H_INCLUDED
 #define RASTER_RASTER_H_INCLUDED
+#pragma once
 
 #include "raster/algo.h"
 #include "raster/blend.h"
diff --git a/src/raster/rgbmap.h b/src/raster/rgbmap.h
index b5f0da249..4a92c0331 100644
--- a/src/raster/rgbmap.h
+++ b/src/raster/rgbmap.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_RGBMAP_H_INCLUDED
 #define RASTER_RGBMAP_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include "raster/object.h"
diff --git a/src/raster/rotate.h b/src/raster/rotate.h
index 2adcef366..52eb78d27 100644
--- a/src/raster/rotate.h
+++ b/src/raster/rotate.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_ROTATE_H_INCLUDED
 #define RASTER_ROTATE_H_INCLUDED
+#pragma once
 
 namespace raster {
 
diff --git a/src/raster/rotsprite.h b/src/raster/rotsprite.h
index 8ca619e8b..319e44294 100644
--- a/src/raster/rotsprite.h
+++ b/src/raster/rotsprite.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_ROTSPRITE_H_INCLUDED
 #define RASTER_ROTSPRITE_H_INCLUDED
+#pragma once
 
 namespace raster {
   class Image;
diff --git a/src/raster/sprite.h b/src/raster/sprite.h
index 8fc5ed330..b0d975644 100644
--- a/src/raster/sprite.h
+++ b/src/raster/sprite.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_SPRITE_H_INCLUDED
 #define RASTER_SPRITE_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include "raster/frame_number.h"
diff --git a/src/raster/sprite_position.h b/src/raster/sprite_position.h
index 82d5a24bf..e15f67b50 100644
--- a/src/raster/sprite_position.h
+++ b/src/raster/sprite_position.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_SPRITE_POSITION_H_INCLUDED
 #define RASTER_SPRITE_POSITION_H_INCLUDED
+#pragma once
 
 #include "raster/frame_number.h"
 #include "raster/layer_index.h"
diff --git a/src/raster/stock.h b/src/raster/stock.h
index 9a849b34a..0c8c94aac 100644
--- a/src/raster/stock.h
+++ b/src/raster/stock.h
@@ -18,6 +18,7 @@
 
 #ifndef RASTER_STOCK_H_INCLUDED
 #define RASTER_STOCK_H_INCLUDED
+#pragma once
 
 #include "raster/object.h"
 #include "raster/pixel_format.h"
diff --git a/src/scripting/engine.h b/src/scripting/engine.h
index e15066fae..a24edb44e 100644
--- a/src/scripting/engine.h
+++ b/src/scripting/engine.h
@@ -18,6 +18,7 @@
 
 #ifndef SCRIPTING_ENGINE_H_INCLUDED
 #define SCRIPTING_ENGINE_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/she/capabilities.h b/src/she/capabilities.h
index d79cafbe4..94c22e66d 100644
--- a/src/she/capabilities.h
+++ b/src/she/capabilities.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_CAPABILITIES_H_INCLUDED
 #define SHE_CAPABILITIES_H_INCLUDED
+#pragma once
 
 namespace she {
 
diff --git a/src/she/display.h b/src/she/display.h
index b3101529d..40b56790a 100644
--- a/src/she/display.h
+++ b/src/she/display.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_DISPLAY_H_INCLUDED
 #define SHE_DISPLAY_H_INCLUDED
+#pragma once
 
 namespace she {
 
diff --git a/src/she/event.h b/src/she/event.h
index 6217cc133..73cbffa39 100644
--- a/src/she/event.h
+++ b/src/she/event.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_EVENT_H_INCLUDED
 #define SHE_EVENT_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <vector>
diff --git a/src/she/event_queue.h b/src/she/event_queue.h
index ee3bcfeae..0f15edb05 100644
--- a/src/she/event_queue.h
+++ b/src/she/event_queue.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_EVENT_QUEUE_H_INCLUDED
 #define SHE_EVENT_QUEUE_H_INCLUDED
+#pragma once
 
 namespace she {
 
diff --git a/src/she/locked_surface.h b/src/she/locked_surface.h
index 8892b9bbe..1c3485fd4 100644
--- a/src/she/locked_surface.h
+++ b/src/she/locked_surface.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_LOCKED_SURFACE_H_INCLUDED
 #define SHE_LOCKED_SURFACE_H_INCLUDED
+#pragma once
 
 namespace she {
 
diff --git a/src/she/scoped_handle.h b/src/she/scoped_handle.h
index a06e6b936..3625b4478 100644
--- a/src/she/scoped_handle.h
+++ b/src/she/scoped_handle.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_SCOPED_HANDLE_H_INCLUDED
 #define SHE_SCOPED_HANDLE_H_INCLUDED
+#pragma once
 
 namespace she {
 
diff --git a/src/she/scoped_surface_lock.h b/src/she/scoped_surface_lock.h
index 01d311d74..f49dcb819 100644
--- a/src/she/scoped_surface_lock.h
+++ b/src/she/scoped_surface_lock.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_SCOPED_SURFACE_LOCK_H_INCLUDED
 #define SHE_SCOPED_SURFACE_LOCK_H_INCLUDED
+#pragma once
 
 #include "she/surface.h"
 #include "she/locked_surface.h"
diff --git a/src/she/she.h b/src/she/she.h
index 3a1096ac7..6d145f8b1 100644
--- a/src/she/she.h
+++ b/src/she/she.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_H_INCLUDED
 #define SHE_H_INCLUDED
+#pragma once
 
 #include "she/display.h"
 #include "she/event.h"
diff --git a/src/she/surface.h b/src/she/surface.h
index b194c7b1f..e4ea59a37 100644
--- a/src/she/surface.h
+++ b/src/she/surface.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_SURFACE_H_INCLUDED
 #define SHE_SURFACE_H_INCLUDED
+#pragma once
 
 namespace she {
 
diff --git a/src/she/system.h b/src/she/system.h
index 90b83918b..63d51d60d 100644
--- a/src/she/system.h
+++ b/src/she/system.h
@@ -6,6 +6,7 @@
 
 #ifndef SHE_SYSTEM_H_INCLUDED
 #define SHE_SYSTEM_H_INCLUDED
+#pragma once
 
 #include "she/capabilities.h"
 #include <stdexcept>
diff --git a/src/tests/test.h b/src/tests/test.h
index a5d7313a4..28e1e6098 100644
--- a/src/tests/test.h
+++ b/src/tests/test.h
@@ -18,6 +18,7 @@
 
 #ifndef TESTS_TEST_H_INCLUDED
 #define TESTS_TEST_H_INCLUDED
+#pragma once
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
diff --git a/src/ui/accelerator.h b/src/ui/accelerator.h
index 567d78358..9b871076e 100644
--- a/src/ui/accelerator.h
+++ b/src/ui/accelerator.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_ACCELERATOR_H_INCLUDED
 #define UI_ACCELERATOR_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <vector>
diff --git a/src/ui/alert.h b/src/ui/alert.h
index eafb7fc4e..e995097d5 100644
--- a/src/ui/alert.h
+++ b/src/ui/alert.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_ALERT_H_INCLUDED
 #define UI_ALERT_H_INCLUDED
+#pragma once
 
 #include "base/shared_ptr.h"
 #include "ui/window.h"
diff --git a/src/ui/base.h b/src/ui/base.h
index 608fdc72c..4dce09937 100644
--- a/src/ui/base.h
+++ b/src/ui/base.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_BASE_H_INCLUDED
 #define UI_BASE_H_INCLUDED
+#pragma once
 
 // Get the system's definition of NULL
 #include <stddef.h>
diff --git a/src/ui/box.h b/src/ui/box.h
index 105b3663c..cc5154dca 100644
--- a/src/ui/box.h
+++ b/src/ui/box.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_BOX_H_INCLUDED
 #define UI_BOX_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/widget.h"
diff --git a/src/ui/button.h b/src/ui/button.h
index 260d3a90d..4c8574ad4 100644
--- a/src/ui/button.h
+++ b/src/ui/button.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_BUTTON_H_INCLUDED
 #define UI_BUTTON_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/ui/clipboard.h b/src/ui/clipboard.h
index 5a449df9d..f15bfcab0 100644
--- a/src/ui/clipboard.h
+++ b/src/ui/clipboard.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_CLIPBOARD_H_INCLUDED
 #define UI_CLIPBOARD_H_INCLUDED
+#pragma once
 
 #include "ui/base.h"
 
diff --git a/src/ui/close_event.h b/src/ui/close_event.h
index d44d66ef5..4d9e1c743 100644
--- a/src/ui/close_event.h
+++ b/src/ui/close_event.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_CLOSE_EVENT_H_INCLUDED
 #define UI_CLOSE_EVENT_H_INCLUDED
+#pragma once
 
 #include "ui/event.h"
 
diff --git a/src/ui/color.h b/src/ui/color.h
index 59e1fd63d..d3d838736 100644
--- a/src/ui/color.h
+++ b/src/ui/color.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_COLOR_H_INCLUDED
 #define UI_COLOR_H_INCLUDED
+#pragma once
 
 namespace ui {
 
diff --git a/src/ui/combobox.h b/src/ui/combobox.h
index 0a1398a29..d4639422d 100644
--- a/src/ui/combobox.h
+++ b/src/ui/combobox.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_COMBOBOX_H_INCLUDED
 #define UI_COMBOBOX_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/ui/component.h b/src/ui/component.h
index fcd3d4979..2a19d28a5 100644
--- a/src/ui/component.h
+++ b/src/ui/component.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_COMPONENT_H_INCLUDED
 #define UI_COMPONENT_H_INCLUDED
+#pragma once
 
 #include <map>
 
diff --git a/src/ui/cursor.h b/src/ui/cursor.h
index e8fbdaa39..1b709f46d 100644
--- a/src/ui/cursor.h
+++ b/src/ui/cursor.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_CURSOR_H_INCLUDED
 #define UI_CURSOR_H_INCLUDED
+#pragma once
 
 #include "gfx/point.h"
 
diff --git a/src/ui/cursor_type.h b/src/ui/cursor_type.h
index c97532b11..ab3cbf752 100644
--- a/src/ui/cursor_type.h
+++ b/src/ui/cursor_type.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_CURSOR_TYPE_H_INCLUDED
 #define UI_CURSOR_TYPE_H_INCLUDED
+#pragma once
 
 namespace ui {
 
diff --git a/src/ui/custom_label.h b/src/ui/custom_label.h
index 888c8ca7e..c24bb0de6 100644
--- a/src/ui/custom_label.h
+++ b/src/ui/custom_label.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_CUSTOM_LABEL_H_INCLUDED
 #define UI_CUSTOM_LABEL_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/label.h"
diff --git a/src/ui/draw.h b/src/ui/draw.h
index 8bf64f3d0..a1dc75149 100644
--- a/src/ui/draw.h
+++ b/src/ui/draw.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_DRAW_H_INCLUDED
 #define UI_DRAW_H_INCLUDED
+#pragma once
 
 #include "gfx/rect.h"
 #include "gfx/region.h"
diff --git a/src/ui/entry.h b/src/ui/entry.h
index 0064eeb20..bf0ee46cd 100644
--- a/src/ui/entry.h
+++ b/src/ui/entry.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_ENTRY_H_INCLUDED
 #define UI_ENTRY_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/ui/event.h b/src/ui/event.h
index e5d5fac7e..1ca9f5d71 100644
--- a/src/ui/event.h
+++ b/src/ui/event.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_EVENT_H_INCLUDED
 #define UI_EVENT_H_INCLUDED
+#pragma once
 
 namespace ui {
 
diff --git a/src/ui/font.h b/src/ui/font.h
index 1b27ca4a7..698d11e77 100644
--- a/src/ui/font.h
+++ b/src/ui/font.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_FONT_H_INCLUDED
 #define UI_FONT_H_INCLUDED
+#pragma once
 
 #include "ui/base.h"
 
diff --git a/src/ui/graphics.h b/src/ui/graphics.h
index cf803e016..ad24a9302 100644
--- a/src/ui/graphics.h
+++ b/src/ui/graphics.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_GRAPHICS_H_INCLUDED
 #define UI_GRAPHICS_H_INCLUDED
+#pragma once
 
 #include "base/shared_ptr.h"
 #include "gfx/point.h"
diff --git a/src/ui/grid.h b/src/ui/grid.h
index 04a783772..a17ca2b92 100644
--- a/src/ui/grid.h
+++ b/src/ui/grid.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_GRID_H_INCLUDED
 #define UI_GRID_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/widget.h"
diff --git a/src/ui/hit_test_event.h b/src/ui/hit_test_event.h
index 2402fd05d..9762eace6 100644
--- a/src/ui/hit_test_event.h
+++ b/src/ui/hit_test_event.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_HIT_TEST_EVENT_H_INCLUDED
 #define UI_HIT_TEST_EVENT_H_INCLUDED
+#pragma once
 
 #include "ui/event.h"
 
diff --git a/src/ui/image_view.h b/src/ui/image_view.h
index 2329f38d6..dac81e7d0 100644
--- a/src/ui/image_view.h
+++ b/src/ui/image_view.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_IMAGE_VIEW_H_INCLUDED
 #define UI_IMAGE_VIEW_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/widget.h"
diff --git a/src/ui/init_theme_event.h b/src/ui/init_theme_event.h
index 7ae58104f..5177d62f6 100644
--- a/src/ui/init_theme_event.h
+++ b/src/ui/init_theme_event.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_INIT_THEME_EVENT_H_INCLUDED
 #define UI_INIT_THEME_EVENT_H_INCLUDED
+#pragma once
 
 #include "ui/event.h"
 
diff --git a/src/ui/int_entry.h b/src/ui/int_entry.h
index 73ab67f00..982590146 100644
--- a/src/ui/int_entry.h
+++ b/src/ui/int_entry.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_INT_ENTRY_H_INCLUDED
 #define UI_INT_ENTRY_H_INCLUDED
+#pragma once
 
 #include "ui/entry.h"
 
diff --git a/src/ui/intern.h b/src/ui/intern.h
index 949b7a829..f66178fea 100644
--- a/src/ui/intern.h
+++ b/src/ui/intern.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_INTERN_H_INCLUDED
 #define UI_INTERN_H_INCLUDED
+#pragma once
 
 #include "ui/base.h"
 #include "ui/color.h"
diff --git a/src/ui/keys.h b/src/ui/keys.h
index dcaf50df0..322a55d7d 100644
--- a/src/ui/keys.h
+++ b/src/ui/keys.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_KEYS_H_INCLUDED
 #define UI_KEYS_H_INCLUDED
+#pragma once
 
 namespace ui {
 
diff --git a/src/ui/label.h b/src/ui/label.h
index 48f84c111..ea00893fe 100644
--- a/src/ui/label.h
+++ b/src/ui/label.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_LABEL_H_INCLUDED
 #define UI_LABEL_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/color.h"
diff --git a/src/ui/layout_io.h b/src/ui/layout_io.h
index 8ba879dc9..00bd14605 100644
--- a/src/ui/layout_io.h
+++ b/src/ui/layout_io.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_LAYOUT_IO_H_INCLUDED
 #define UI_LAYOUT_IO_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/ui/link_label.h b/src/ui/link_label.h
index f4c99c4d7..ab7bfdbca 100644
--- a/src/ui/link_label.h
+++ b/src/ui/link_label.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_LINK_LABEL_H_INCLUDED
 #define UI_LINK_LABEL_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/ui/listbox.h b/src/ui/listbox.h
index 4d7ef152e..260d1d0b2 100644
--- a/src/ui/listbox.h
+++ b/src/ui/listbox.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_LISTBOX_H_INCLUDED
 #define UI_LISTBOX_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/ui/listitem.h b/src/ui/listitem.h
index 9af36e77e..78bc9faf7 100644
--- a/src/ui/listitem.h
+++ b/src/ui/listitem.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_LISTITEM_H_INCLUDED
 #define UI_LISTITEM_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/widget.h"
diff --git a/src/ui/load_layout_event.h b/src/ui/load_layout_event.h
index fc49bd374..152489123 100644
--- a/src/ui/load_layout_event.h
+++ b/src/ui/load_layout_event.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_LOAD_LAYOUT_EVENT_H_INCLUDED
 #define UI_LOAD_LAYOUT_EVENT_H_INCLUDED
+#pragma once
 
 #include "ui/event.h"
 #include <iosfwd>
diff --git a/src/ui/manager.h b/src/ui/manager.h
index 0045854d5..f5a837025 100644
--- a/src/ui/manager.h
+++ b/src/ui/manager.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_MANAGER_H_INCLUDED
 #define UI_MANAGER_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/message_type.h"
diff --git a/src/ui/menu.h b/src/ui/menu.h
index 05896ef2e..c6e764d6e 100644
--- a/src/ui/menu.h
+++ b/src/ui/menu.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_MENU_H_INCLUDED
 #define UI_MENU_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/ui/message.h b/src/ui/message.h
index 6386653d9..dded20d7b 100644
--- a/src/ui/message.h
+++ b/src/ui/message.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_MESSAGE_H_INCLUDED
 #define UI_MESSAGE_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "gfx/point.h"
diff --git a/src/ui/message_loop.h b/src/ui/message_loop.h
index 779e2dbc9..f6f5e0ab0 100644
--- a/src/ui/message_loop.h
+++ b/src/ui/message_loop.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_MESSAGE_LOOP_H_INCLUDED
 #define UI_MESSAGE_LOOP_H_INCLUDED
+#pragma once
 
 namespace ui {
 
diff --git a/src/ui/message_type.h b/src/ui/message_type.h
index b0e588036..fdc006aa7 100644
--- a/src/ui/message_type.h
+++ b/src/ui/message_type.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_MESSAGE_TYPE_H_INCLUDED
 #define UI_MESSAGE_TYPE_H_INCLUDED
+#pragma once
 
 namespace ui {
 
diff --git a/src/ui/mouse_buttons.h b/src/ui/mouse_buttons.h
index 10547315f..b711b9f60 100644
--- a/src/ui/mouse_buttons.h
+++ b/src/ui/mouse_buttons.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_MOUSE_BUTTONS_H_INCLUDED
 #define UI_MOUSE_BUTTONS_H_INCLUDED
+#pragma once
 
 namespace ui {
 
diff --git a/src/ui/overlay.h b/src/ui/overlay.h
index bfd691245..b8be64f1d 100644
--- a/src/ui/overlay.h
+++ b/src/ui/overlay.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_OVERLAY_H_INCLUDED
 #define UI_OVERLAY_H_INCLUDED
+#pragma once
 
 #include "gfx/fwd.h"
 #include "gfx/point.h"
diff --git a/src/ui/overlay_manager.h b/src/ui/overlay_manager.h
index 665970da7..e51c9bc94 100644
--- a/src/ui/overlay_manager.h
+++ b/src/ui/overlay_manager.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_OVERLAY_MANAGER_H_INCLUDED
 #define UI_OVERLAY_MANAGER_H_INCLUDED
+#pragma once
 
 #include "ui/base.h"
 #include <vector>
diff --git a/src/ui/paint_event.h b/src/ui/paint_event.h
index 100c9c58c..8743facbb 100644
--- a/src/ui/paint_event.h
+++ b/src/ui/paint_event.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_PAINT_EVENT_H_INCLUDED
 #define UI_PAINT_EVENT_H_INCLUDED
+#pragma once
 
 #include "ui/event.h"
 
diff --git a/src/ui/popup_window.h b/src/ui/popup_window.h
index f8fbb6edf..a2d88ee2c 100644
--- a/src/ui/popup_window.h
+++ b/src/ui/popup_window.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_POPUP_WINDOW_H_INCLUDED
 #define UI_POPUP_WINDOW_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/window.h"
diff --git a/src/ui/preferred_size_event.h b/src/ui/preferred_size_event.h
index c0d60443b..a3886049b 100644
--- a/src/ui/preferred_size_event.h
+++ b/src/ui/preferred_size_event.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_PREFERRED_SIZE_EVENT_H_INCLUDED
 #define UI_PREFERRED_SIZE_EVENT_H_INCLUDED
+#pragma once
 
 #include "gfx/size.h"
 #include "ui/event.h"
diff --git a/src/ui/property.h b/src/ui/property.h
index 4a5585f62..4fdb47c7c 100644
--- a/src/ui/property.h
+++ b/src/ui/property.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_PROPERTY_H_INCLUDED
 #define UI_PROPERTY_H_INCLUDED
+#pragma once
 
 #include "base/string.h"
 #include "base/disable_copying.h"
diff --git a/src/ui/register_message.h b/src/ui/register_message.h
index 4e9751543..2adc5d5ed 100644
--- a/src/ui/register_message.h
+++ b/src/ui/register_message.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_REGISTER_MESSAGE_H_INCLUDED
 #define UI_REGISTER_MESSAGE_H_INCLUDED
+#pragma once
 
 #include "ui/message_type.h"
 
diff --git a/src/ui/resize_event.h b/src/ui/resize_event.h
index ddc81eeb3..f6697b701 100644
--- a/src/ui/resize_event.h
+++ b/src/ui/resize_event.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_RESIZE_EVENT_H_INCLUDED
 #define UI_RESIZE_EVENT_H_INCLUDED
+#pragma once
 
 #include "gfx/rect.h"
 #include "ui/event.h"
diff --git a/src/ui/save_layout_event.h b/src/ui/save_layout_event.h
index 620c8415a..3a636927c 100644
--- a/src/ui/save_layout_event.h
+++ b/src/ui/save_layout_event.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_SAVE_LAYOUT_EVENT_H_INCLUDED
 #define UI_SAVE_LAYOUT_EVENT_H_INCLUDED
+#pragma once
 
 #include "ui/event.h"
 #include <iosfwd>
diff --git a/src/ui/scroll_bar.h b/src/ui/scroll_bar.h
index 6a7a7f397..260765ccd 100644
--- a/src/ui/scroll_bar.h
+++ b/src/ui/scroll_bar.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_SCROLL_BAR_H_INCLUDED
 #define UI_SCROLL_BAR_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/widget.h"
diff --git a/src/ui/separator.h b/src/ui/separator.h
index 57ea20f5d..b664afb59 100644
--- a/src/ui/separator.h
+++ b/src/ui/separator.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_SEPARATOR_H_INCLUDED
 #define UI_SEPARATOR_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/widget.h"
diff --git a/src/ui/slider.h b/src/ui/slider.h
index 0e9d39414..80f9690e1 100644
--- a/src/ui/slider.h
+++ b/src/ui/slider.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_SLIDER_H_INCLUDED
 #define UI_SLIDER_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/ui/splitter.h b/src/ui/splitter.h
index 193908c9d..9122c2bb2 100644
--- a/src/ui/splitter.h
+++ b/src/ui/splitter.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_SPLITTER_H_INCLUDED
 #define UI_SPLITTER_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/widget.h"
diff --git a/src/ui/system.h b/src/ui/system.h
index d6b4cd7e9..d1804bbcb 100644
--- a/src/ui/system.h
+++ b/src/ui/system.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_SYSTEM_H_INCLUDED
 #define UI_SYSTEM_H_INCLUDED
+#pragma once
 
 #include "gfx/fwd.h"
 #include "ui/base.h"
diff --git a/src/ui/textbox.h b/src/ui/textbox.h
index 460984c86..954fcd219 100644
--- a/src/ui/textbox.h
+++ b/src/ui/textbox.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_TEXTBOX_H_INCLUDED
 #define UI_TEXTBOX_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/widget.h"
diff --git a/src/ui/theme.h b/src/ui/theme.h
index b3ffb0460..d2396a206 100644
--- a/src/ui/theme.h
+++ b/src/ui/theme.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_THEME_H_INCLUDED
 #define UI_THEME_H_INCLUDED
+#pragma once
 
 #include "ui/base.h"
 #include "ui/cursor_type.h"
diff --git a/src/ui/timer.h b/src/ui/timer.h
index 944e7b5ba..6fd0ef36a 100644
--- a/src/ui/timer.h
+++ b/src/ui/timer.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_TIMER_H_INCLUDED
 #define UI_TIMER_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include "base/signal.h"
diff --git a/src/ui/tooltips.h b/src/ui/tooltips.h
index 613193912..4da9b7b62 100644
--- a/src/ui/tooltips.h
+++ b/src/ui/tooltips.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_TOOLTIPS_H_INCLUDED
 #define UI_TOOLTIPS_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/base.h"
diff --git a/src/ui/ui.h b/src/ui/ui.h
index ff38e205c..bbc7d4b79 100644
--- a/src/ui/ui.h
+++ b/src/ui/ui.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_UI_H_INCLUDED
 #define UI_UI_H_INCLUDED
+#pragma once
 
 #include "ui/accelerator.h"
 #include "ui/alert.h"
diff --git a/src/ui/view.h b/src/ui/view.h
index cc454f6b8..83962669f 100644
--- a/src/ui/view.h
+++ b/src/ui/view.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_VIEW_H_INCLUDED
 #define UI_VIEW_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "gfx/point.h"
diff --git a/src/ui/viewport.h b/src/ui/viewport.h
index 23f1c8aab..654efe7cd 100644
--- a/src/ui/viewport.h
+++ b/src/ui/viewport.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_VIEWPORT_H_INCLUDED
 #define UI_VIEWPORT_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/widget.h"
diff --git a/src/ui/widget.h b/src/ui/widget.h
index cc7e748ab..967a4951e 100644
--- a/src/ui/widget.h
+++ b/src/ui/widget.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_WIDGET_H_INCLUDED
 #define UI_WIDGET_H_INCLUDED
+#pragma once
 
 #include <string>
 
diff --git a/src/ui/widget_type.h b/src/ui/widget_type.h
index 87cc9dc09..7d807bd3b 100644
--- a/src/ui/widget_type.h
+++ b/src/ui/widget_type.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_WIDGET_TYPE_H_INCLUDED
 #define UI_WIDGET_TYPE_H_INCLUDED
+#pragma once
 
 namespace ui {
 
diff --git a/src/ui/widgets_list.h b/src/ui/widgets_list.h
index f709dd3ed..012b6cd72 100644
--- a/src/ui/widgets_list.h
+++ b/src/ui/widgets_list.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_WIDGETS_LIST_H_INCLUDED
 #define UI_WIDGETS_LIST_H_INCLUDED
+#pragma once
 
 #include <vector>
 
diff --git a/src/ui/window.h b/src/ui/window.h
index f7a35a7a0..58427832a 100644
--- a/src/ui/window.h
+++ b/src/ui/window.h
@@ -6,6 +6,7 @@
 
 #ifndef UI_WINDOW_H_INCLUDED
 #define UI_WINDOW_H_INCLUDED
+#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/signal.h"
diff --git a/src/undo/modification.h b/src/undo/modification.h
index f3cd9398d..546c3ab15 100644
--- a/src/undo/modification.h
+++ b/src/undo/modification.h
@@ -6,6 +6,7 @@
 
 #ifndef UNDO_MODIFICATION_H_INCLUDED
 #define UNDO_MODIFICATION_H_INCLUDED
+#pragma once
 
 namespace undo {
 
diff --git a/src/undo/object_id.h b/src/undo/object_id.h
index fc46a4c1e..36576e42d 100644
--- a/src/undo/object_id.h
+++ b/src/undo/object_id.h
@@ -6,6 +6,7 @@
 
 #ifndef UNDO_OBJECT_ID_H_INCLUDED
 #define UNDO_OBJECT_ID_H_INCLUDED
+#pragma once
 
 namespace undo {
 
diff --git a/src/undo/objects_container.h b/src/undo/objects_container.h
index 5a42f98ee..00c195082 100644
--- a/src/undo/objects_container.h
+++ b/src/undo/objects_container.h
@@ -6,6 +6,7 @@
 
 #ifndef UNDO_OBJECTS_CONTAINER_H_INCLUDED
 #define UNDO_OBJECTS_CONTAINER_H_INCLUDED
+#pragma once
 
 #include "undo/object_id.h"
 
diff --git a/src/undo/undo_exception.h b/src/undo/undo_exception.h
index 26324877f..6d21697d1 100644
--- a/src/undo/undo_exception.h
+++ b/src/undo/undo_exception.h
@@ -6,6 +6,7 @@
 
 #ifndef UNDO_UNDO_EXCEPTION_H_INCLUDED
 #define UNDO_UNDO_EXCEPTION_H_INCLUDED
+#pragma once
 
 #include <stdexcept>
 
diff --git a/src/undo/undo_history.h b/src/undo/undo_history.h
index 9d4090fc2..c50f68424 100644
--- a/src/undo/undo_history.h
+++ b/src/undo/undo_history.h
@@ -6,6 +6,7 @@
 
 #ifndef UNDO_UNDO_HISTORY_H_INCLUDED
 #define UNDO_UNDO_HISTORY_H_INCLUDED
+#pragma once
 
 #include "undo/modification.h"
 #include "undo/undoers_collector.h"
diff --git a/src/undo/undoer.h b/src/undo/undoer.h
index c8d35ccbe..af1e54aec 100644
--- a/src/undo/undoer.h
+++ b/src/undo/undoer.h
@@ -6,6 +6,7 @@
 
 #ifndef UNDO_UNDOER_H_INCLUDED
 #define UNDO_UNDOER_H_INCLUDED
+#pragma once
 
 #include "undo/modification.h"
 
diff --git a/src/undo/undoers_collector.h b/src/undo/undoers_collector.h
index 00750fdc4..a3a70d640 100644
--- a/src/undo/undoers_collector.h
+++ b/src/undo/undoers_collector.h
@@ -6,6 +6,7 @@
 
 #ifndef UNDO_UNDOERS_COLLECTOR_H_INCLUDED
 #define UNDO_UNDOERS_COLLECTOR_H_INCLUDED
+#pragma once
 
 namespace undo {
 
diff --git a/src/undo/undoers_stack.h b/src/undo/undoers_stack.h
index b1b5809f1..4153920a5 100644
--- a/src/undo/undoers_stack.h
+++ b/src/undo/undoers_stack.h
@@ -6,6 +6,7 @@
 
 #ifndef UNDO_UNDOERS_STACK_H_INCLUDED
 #define UNDO_UNDOERS_STACK_H_INCLUDED
+#pragma once
 
 #include "undo/undoers_collector.h"
 
diff --git a/src/updater/check_update.h b/src/updater/check_update.h
index 56a35c767..36ebf4e18 100644
--- a/src/updater/check_update.h
+++ b/src/updater/check_update.h
@@ -18,6 +18,7 @@
 
 #ifndef UPDATER_CHECK_UPDATE_H_INCLUDED
 #define UPDATER_CHECK_UPDATE_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include "base/version.h"
diff --git a/src/updater/user_agent.h b/src/updater/user_agent.h
index bf234bfe8..73f72096a 100644
--- a/src/updater/user_agent.h
+++ b/src/updater/user_agent.h
@@ -18,6 +18,7 @@
 
 #ifndef UPDATER_USER_AGENT_H_INCLUDED
 #define UPDATER_USER_AGENT_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 
diff --git a/src/webserver/webserver.h b/src/webserver/webserver.h
index 3af89b64c..81775e87e 100644
--- a/src/webserver/webserver.h
+++ b/src/webserver/webserver.h
@@ -18,6 +18,7 @@
 
 #ifndef WEBSERVER_WEBSERVER_H_INCLUDED
 #define WEBSERVER_WEBSERVER_H_INCLUDED
+#pragma once
 
 #include "base/disable_copying.h"
 #include <string>