diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 1c645075e..62e408125 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -141,6 +141,7 @@ add_library(aseprite-library
   context_flags.cpp
   context_listener_list.cpp
   document.cpp
+  document_undo.cpp
   documents.cpp
   drop_files.cpp
   file_system.cpp
diff --git a/src/commands/cmd_cel_properties.cpp b/src/commands/cmd_cel_properties.cpp
index 246303672..bd6da95c0 100644
--- a/src/commands/cmd_cel_properties.cpp
+++ b/src/commands/cmd_cel_properties.cpp
@@ -31,7 +31,7 @@
 #include "raster/sprite.h"
 #include "raster/stock.h"
 #include "ui/gui.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "undoers/set_cel_opacity.h"
 
 #include <allegro/unicode.h>
@@ -129,18 +129,16 @@ void CelPropertiesCommand::onExecute(Context* context)
     Sprite* sprite_writer = document_writer->getSprite();
     Layer* layer_writer = sprite_writer->getCurrentLayer();
     Cel* cel_writer = static_cast<LayerImage*>(layer_writer)->getCel(sprite->getCurrentFrame());
-    undo::UndoHistory* undo = document_writer->getUndoHistory();
 
     int new_opacity = slider_opacity->getValue();
 
     // The opacity was changed?
     if (cel_writer != NULL &&
         cel_writer->getOpacity() != new_opacity) {
-      if (undo->isEnabled()) {
-        undo->setLabel("Cel Opacity Change");
-        undo->setModification(undo::ModifyDocument);
-
-        undo->pushUndoer(new undoers::SetCelOpacity(undo->getObjects(), cel_writer));
+      UndoTransaction undo(document_writer, "Cel Opacity Change", undo::ModifyDocument);
+      if (undo.isEnabled()) {
+        undo.pushUndoer(new undoers::SetCelOpacity(undo.getObjects(), cel_writer));
+        undo.commit();
       }
 
       // Change cel opacity.
diff --git a/src/commands/cmd_duplicate_layer.cpp b/src/commands/cmd_duplicate_layer.cpp
index 4e5235d5c..2df62bfe5 100644
--- a/src/commands/cmd_duplicate_layer.cpp
+++ b/src/commands/cmd_duplicate_layer.cpp
@@ -21,12 +21,12 @@
 #include "app.h"
 #include "commands/command.h"
 #include "console.h"
+#include "document_undo.h"
 #include "document_wrappers.h"
 #include "modules/gui.h"
 #include "raster/layer.h"
 #include "raster/sprite.h"
 #include "ui/gui.h"
-#include "undo/undo_history.h"
 #include "undo_transaction.h"
 #include "undoers/add_layer.h"
 #include "undoers/move_layer.h"
@@ -64,8 +64,7 @@ void DuplicateLayerCommand::onExecute(Context* context)
 {
   ActiveDocumentWriter document(context);
   Sprite* sprite = document->getSprite();
-  undo::UndoHistory* undo = document->getUndoHistory();
-  UndoTransaction undoTransaction(document, "Layer Duplication");
+  UndoTransaction undo(document, "Layer Duplication");
   LayerImage* sourceLayer = static_cast<LayerImage*>(sprite->getCurrentLayer());
 
   // Create a new layer
@@ -73,20 +72,20 @@ void DuplicateLayerCommand::onExecute(Context* context)
 
   // Disable undo because the layer content is added as a whole with
   // AddLayer() undoer.
-  document->getUndoHistory()->setEnabled(false);
+  document->getUndo()->setEnabled(false);
 
   // Copy the layer content (cels + images)
   document->copyLayerContent(sourceLayer, document, newLayerPtr);
 
   // Restore enabled status.
-  document->getUndoHistory()->setEnabled(undoTransaction.isEnabled());
+  document->getUndo()->setEnabled(undo.isEnabled());
 
   // Copy the layer name
   newLayerPtr->setName(newLayerPtr->getName() + " Copy");
 
   // Add the new layer in the sprite.
-  if (undo->isEnabled())
-    undo->pushUndoer(new undoers::AddLayer(undo->getObjects(),
+  if (undo.isEnabled())
+    undo.pushUndoer(new undoers::AddLayer(undo.getObjects(),
         sourceLayer->get_parent(), newLayerPtr));
 
   sourceLayer->get_parent()->add_layer(newLayerPtr);
@@ -94,12 +93,12 @@ void DuplicateLayerCommand::onExecute(Context* context)
   // Release the pointer as it is owned by the sprite now
   Layer* newLayer = newLayerPtr.release();
 
-  if (undo->isEnabled()) {
-    undo->pushUndoer(new undoers::MoveLayer(undo->getObjects(), newLayer));
-    undo->pushUndoer(new undoers::SetCurrentLayer(undo->getObjects(), sprite));
+  if (undo.isEnabled()) {
+    undo.pushUndoer(new undoers::MoveLayer(undo.getObjects(), newLayer));
+    undo.pushUndoer(new undoers::SetCurrentLayer(undo.getObjects(), sprite));
   }
 
-  undoTransaction.commit();
+  undo.commit();
 
   sourceLayer->get_parent()->move_layer(newLayer, sourceLayer);
   sprite->setCurrentLayer(newLayer);
diff --git a/src/commands/cmd_export_sprite_sheet.cpp b/src/commands/cmd_export_sprite_sheet.cpp
index 1897c554f..15214cf06 100644
--- a/src/commands/cmd_export_sprite_sheet.cpp
+++ b/src/commands/cmd_export_sprite_sheet.cpp
@@ -21,6 +21,7 @@
 #include "base/bind.h"
 #include "commands/command.h"
 #include "commands/commands.h"
+#include "document_undo.h"
 #include "document_wrappers.h"
 #include "ini_file.h"
 #include "modules/gui.h"
@@ -32,7 +33,6 @@
 #include "raster/sprite.h"
 #include "raster/stock.h"
 #include "ui/gui.h"
-#include "undo/undo_history.h"
 #include "undo_transaction.h"
 
 #include <limits>
@@ -257,7 +257,9 @@ protected:
 
     // Undo the sprite sheet conversion
     if (undo) {
-      m_document->getUndoHistory()->doUndo();
+      if (m_document->getUndo()->canUndo())
+        m_document->getUndo()->doUndo();
+
       m_document->generateMaskBoundaries();
       m_document->destroyExtraCel(); // Regenerate extras
 
diff --git a/src/commands/cmd_invert_mask.cpp b/src/commands/cmd_invert_mask.cpp
index 2d1de10c3..46c37d896 100644
--- a/src/commands/cmd_invert_mask.cpp
+++ b/src/commands/cmd_invert_mask.cpp
@@ -26,7 +26,7 @@
 #include "raster/image.h"
 #include "raster/mask.h"
 #include "raster/sprite.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "undoers/set_mask.h"
 
 //////////////////////////////////////////////////////////////////////
@@ -76,14 +76,9 @@ void InvertMaskCommand::onExecute(Context* context)
   else {
     ActiveDocumentWriter document(context);
     Sprite* sprite(document->getSprite());
-    undo::UndoHistory* undo = document->getUndoHistory();
-
-    /* undo */
-    if (undo->isEnabled()) {
-      undo->setLabel("Mask Invert");
-      undo->setModification(undo::DoesntModifyDocument);
-      undo->pushUndoer(new undoers::SetMask(undo->getObjects(), document));
-    }
+    UndoTransaction undo(document, "Mask Invert", undo::DoesntModifyDocument);
+    if (undo.isEnabled())
+      undo.pushUndoer(new undoers::SetMask(undo.getObjects(), document));
 
     /* create a new mask */
     UniquePtr<Mask> mask(new Mask());
@@ -108,11 +103,12 @@ void InvertMaskCommand::onExecute(Context* context)
                  document->getMask()->getBounds().y);
     }
 
-    /* we need only need the area inside the sprite */
+    // We need only need the area inside the sprite
     mask->intersect(0, 0, sprite->getWidth(), sprite->getHeight());
 
     // Set the new mask
     document->setMask(mask);
+    undo.commit();
 
     document->generateMaskBoundaries();
     update_screen_for_document(document);
diff --git a/src/commands/cmd_load_mask.cpp b/src/commands/cmd_load_mask.cpp
index ec2d8b2b7..6ed644c81 100644
--- a/src/commands/cmd_load_mask.cpp
+++ b/src/commands/cmd_load_mask.cpp
@@ -26,7 +26,7 @@
 #include "raster/mask.h"
 #include "raster/sprite.h"
 #include "ui/alert.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "undoers/set_mask.h"
 #include "util/msk_file.h"
 
@@ -84,16 +84,15 @@ void LoadMaskCommand::onExecute(Context* context)
 
   {
     DocumentWriter documentWriter(document);
-    undo::UndoHistory* undo(documentWriter->getUndoHistory());
+    UndoTransaction undo(documentWriter, "Mask Load", undo::DoesntModifyDocument);
 
     // Add the mask change into the undo history.
-    if (undo->isEnabled()) {
-      undo->setLabel("Mask Load");
-      undo->setModification(undo::DoesntModifyDocument);
-      undo->pushUndoer(new undoers::SetMask(undo->getObjects(), documentWriter));
-    }
+    if (undo.isEnabled())
+      undo.pushUndoer(new undoers::SetMask(undo.getObjects(), documentWriter));
 
     documentWriter->setMask(mask);
+
+    undo.commit();
     documentWriter->generateMaskBoundaries();
   }
 
diff --git a/src/commands/cmd_mask_all.cpp b/src/commands/cmd_mask_all.cpp
index eaab0d13f..9d32fcf81 100644
--- a/src/commands/cmd_mask_all.cpp
+++ b/src/commands/cmd_mask_all.cpp
@@ -23,7 +23,7 @@
 #include "modules/gui.h"
 #include "raster/mask.h"
 #include "raster/sprite.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "undoers/set_mask.h"
 
 //////////////////////////////////////////////////////////////////////
@@ -57,20 +57,18 @@ void MaskAllCommand::onExecute(Context* context)
 {
   ActiveDocumentWriter document(context);
   Sprite* sprite(document->getSprite());
-  undo::UndoHistory* undo(document->getUndoHistory());
+  UndoTransaction undo(document, "Mask All", undo::DoesntModifyDocument);
 
   // Undo
-  if (undo->isEnabled()) {
-    undo->setLabel("Mask All");
-    undo->setModification(undo::DoesntModifyDocument);
-    undo->pushUndoer(new undoers::SetMask(undo->getObjects(), document));
-  }
+  if (undo.isEnabled())
+    undo.pushUndoer(new undoers::SetMask(undo.getObjects(), document));
 
   // Change the selection
   document->getMask()->replace(0, 0, sprite->getWidth(), sprite->getHeight());
   document->setMaskVisible(true);
   document->resetTransformation();
 
+  undo.commit();
   document->generateMaskBoundaries();
   update_screen_for_document(document);
 }
diff --git a/src/commands/cmd_merge_down_layer.cpp b/src/commands/cmd_merge_down_layer.cpp
index aa8a2ac4a..f0548ba03 100644
--- a/src/commands/cmd_merge_down_layer.cpp
+++ b/src/commands/cmd_merge_down_layer.cpp
@@ -28,11 +28,9 @@
 #include "raster/sprite.h"
 #include "raster/stock.h"
 #include "ui/gui.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "undoers/add_cel.h"
 #include "undoers/add_image.h"
-#include "undoers/close_group.h"
-#include "undoers/open_group.h"
 #include "undoers/remove_layer.h"
 #include "undoers/replace_image.h"
 #include "undoers/set_cel_position.h"
@@ -81,7 +79,7 @@ void MergeDownLayerCommand::onExecute(Context* context)
 {
   ActiveDocumentWriter document(context);
   Sprite* sprite(document->getSprite());
-  undo::UndoHistory* undo(document->getUndoHistory());
+  UndoTransaction undo(document, "Merge Down Layer", undo::ModifyDocument);
   Layer *src_layer, *dst_layer;
   Cel *src_cel, *dst_cel;
   Image *src_image, *dst_image;
@@ -90,12 +88,6 @@ void MergeDownLayerCommand::onExecute(Context* context)
   src_layer = sprite->getCurrentLayer();
   dst_layer = sprite->getCurrentLayer()->get_prev();
 
-  if (undo->isEnabled()) {
-    undo->setLabel("Merge Down Layer");
-    undo->setModification(undo::ModifyDocument);
-    undo->pushUndoer(new undoers::OpenGroup());
-  }
-
   for (frpos=0; frpos<sprite->getTotalFrames(); ++frpos) {
     // Get frames
     src_cel = static_cast<LayerImage*>(src_layer)->getCel(frpos);
@@ -123,17 +115,17 @@ void MergeDownLayerCommand::onExecute(Context* context)
 
         // Adding it in the stock of images
         index = sprite->getStock()->addImage(dst_image);
-        if (undo->isEnabled())
-          undo->pushUndoer(new undoers::AddImage(
-              undo->getObjects(), sprite->getStock(), index));
+        if (undo.isEnabled())
+          undo.pushUndoer(new undoers::AddImage(
+              undo.getObjects(), sprite->getStock(), index));
 
         // Creating a copy of the cell
         dst_cel = new Cel(frpos, index);
         dst_cel->setPosition(src_cel->getX(), src_cel->getY());
         dst_cel->setOpacity(src_cel->getOpacity());
 
-        if (undo->isEnabled())
-          undo->pushUndoer(new undoers::AddCel(undo->getObjects(), dst_layer, dst_cel));
+        if (undo.isEnabled())
+          undo.pushUndoer(new undoers::AddCel(undo.getObjects(), dst_layer, dst_cel));
 
         static_cast<LayerImage*>(dst_layer)->addCel(dst_cel);
       }
@@ -171,13 +163,13 @@ void MergeDownLayerCommand::onExecute(Context* context)
                     src_cel->getOpacity(),
                     static_cast<LayerImage*>(src_layer)->getBlendMode());
 
-        if (undo->isEnabled())
-          undo->pushUndoer(new undoers::SetCelPosition(undo->getObjects(), dst_cel));
+        if (undo.isEnabled())
+          undo.pushUndoer(new undoers::SetCelPosition(undo.getObjects(), dst_cel));
 
         dst_cel->setPosition(x1, y1);
 
-        if (undo->isEnabled())
-          undo->pushUndoer(new undoers::ReplaceImage(undo->getObjects(),
+        if (undo.isEnabled())
+          undo.pushUndoer(new undoers::ReplaceImage(undo.getObjects(),
               sprite->getStock(), dst_cel->getImage()));
 
         sprite->getStock()->replaceImage(dst_cel->getImage(), new_image);
@@ -187,10 +179,9 @@ void MergeDownLayerCommand::onExecute(Context* context)
     }
   }
 
-  if (undo->isEnabled()) {
-    undo->pushUndoer(new undoers::SetCurrentLayer(undo->getObjects(), sprite));
-    undo->pushUndoer(new undoers::RemoveLayer(undo->getObjects(), src_layer));
-    undo->pushUndoer(new undoers::CloseGroup());
+  if (undo.isEnabled()) {
+    undo.pushUndoer(new undoers::SetCurrentLayer(undo.getObjects(), sprite));
+    undo.pushUndoer(new undoers::RemoveLayer(undo.getObjects(), src_layer));
   }
 
   sprite->setCurrentLayer(dst_layer);
@@ -198,6 +189,7 @@ void MergeDownLayerCommand::onExecute(Context* context)
 
   delete src_layer;
 
+  undo.commit();
   update_screen_for_document(document);
 }
 
diff --git a/src/commands/cmd_palette_editor.cpp b/src/commands/cmd_palette_editor.cpp
index 9624a9369..f83b20b2b 100644
--- a/src/commands/cmd_palette_editor.cpp
+++ b/src/commands/cmd_palette_editor.cpp
@@ -27,6 +27,7 @@
 #include "commands/command.h"
 #include "commands/params.h"
 #include "console.h"
+#include "document_undo.h"
 #include "document_wrappers.h"
 #include "gfx/hsv.h"
 #include "gfx/rgb.h"
@@ -44,9 +45,7 @@
 #include "ui/graphics.h"
 #include "ui/gui.h"
 #include "ui_context.h"
-#include "undo/undo_history.h"
-#include "undoers/close_group.h"
-#include "undoers/open_group.h"
+#include "undo_transaction.h"
 #include "undoers/set_palette_colors.h"
 #include "widgets/color_bar.h"
 #include "widgets/color_sliders.h"
@@ -123,10 +122,10 @@ private:
   ui::Timer m_redrawTimer;
   bool m_redrawAll;
 
-  // True if the palette change must be graft in the UndoHistory
+  // True if the palette change must be implant in the UndoHistory
   // (e.g. when two or more changes in the palette are made in short
   // time).
-  bool m_graftChange;
+  bool m_implantChange;
 
   // True if the PaletteChange signal is generated by the same
   // PaletteEntryEditor instance.
@@ -261,7 +260,7 @@ PaletteEntryEditor::PaletteEntryEditor()
   , m_quantizeButton("Quantize")
   , m_disableHexUpdate(false)
   , m_redrawAll(false)
-  , m_graftChange(false)
+  , m_implantChange(false)
   , m_selfPalChange(false)
   , m_redrawTimer(250, this)
 {
@@ -403,7 +402,7 @@ bool PaletteEntryEditor::onProcessMessage(Message* msg)
     // Redraw all editors
     if (m_redrawAll) {
       m_redrawAll = false;
-      m_graftChange = false;
+      m_implantChange = false;
       m_redrawTimer.stop();
 
       // Call all listener of PaletteChange event.
@@ -803,7 +802,6 @@ void PaletteEntryEditor::updateCurrentSpritePalette(const char* operationName)
     try {
       ActiveDocumentWriter document(UIContext::instance());
       Sprite* sprite(document->getSprite());
-      undo::UndoHistory* undo = document->getUndoHistory();
       Palette* newPalette = get_current_palette(); // System current pal
       Palette* currentSpritePalette = sprite->getPalette(sprite->getCurrentFrame()); // Sprite current pal
       int from, to;
@@ -813,23 +811,21 @@ void PaletteEntryEditor::updateCurrentSpritePalette(const char* operationName)
       currentSpritePalette->countDiff(newPalette, &from, &to);
 
       if (from >= 0 && to >= from) {
+        DocumentUndo* undo = document->getUndo();
+
         // Add undo information to save the range of pal entries that will be modified.
         if (undo->isEnabled()) {
-          if (m_graftChange && strcmp(undo->getLabel(), operationName) == 0) {
-            undo->setLabel(operationName);
-            undo->setModification(undo::ModifyDocument);
-
-            undo->graftUndoerInLastGroup(new undoers::SetPaletteColors(undo->getObjects(),
-                                                                       sprite, currentSpritePalette, from, to));
+          if (m_implantChange && strcmp(undo->getNextUndoLabel(), operationName) == 0) {
+            undo->implantUndoerInLastGroup
+              (new undoers::SetPaletteColors(undo->getObjects(),
+                                             sprite, currentSpritePalette, from, to));
           }
           else {
-            undo->setLabel(operationName);
-            undo->setModification(undo::ModifyDocument);
-
-            undo->pushUndoer(new undoers::OpenGroup());
-            undo->pushUndoer(new undoers::SetPaletteColors(undo->getObjects(),
-                                                           sprite, currentSpritePalette, from, to));
-            undo->pushUndoer(new undoers::CloseGroup());
+            UndoTransaction undoTransaction(document, operationName, undo::ModifyDocument);
+            undoTransaction.pushUndoer
+              (new undoers::SetPaletteColors(undoTransaction.getObjects(),
+                                             sprite, currentSpritePalette, from, to));
+            undoTransaction.commit();
           }
         }
 
@@ -849,7 +845,7 @@ void PaletteEntryEditor::updateCurrentSpritePalette(const char* operationName)
     m_redrawTimer.start();
 
   m_redrawAll = false;
-  m_graftChange = true;
+  m_implantChange = true;
 }
 
 void PaletteEntryEditor::updateColorBar()
diff --git a/src/commands/cmd_redo.cpp b/src/commands/cmd_redo.cpp
index a992440a9..44affd6c6 100644
--- a/src/commands/cmd_redo.cpp
+++ b/src/commands/cmd_redo.cpp
@@ -20,10 +20,10 @@
 
 #include "app.h"
 #include "commands/command.h"
+#include "document_undo.h"
 #include "document_wrappers.h"
 #include "modules/gui.h"
 #include "raster/sprite.h"
-#include "undo/undo_history.h"
 #include "widgets/status_bar.h"
 
 class RedoCommand : public Command
@@ -49,7 +49,7 @@ bool RedoCommand::onEnabled(Context* context)
   ActiveDocumentWriter document(context);
   return
     document != NULL &&
-    document->getUndoHistory()->canRedo();
+    document->getUndo()->canRedo();
 }
 
 void RedoCommand::onExecute(Context* context)
@@ -58,9 +58,9 @@ void RedoCommand::onExecute(Context* context)
 
   app_get_statusbar()
     ->showTip(1000, "Redid %s",
-              document->getUndoHistory()->getNextRedoLabel());
+              document->getUndo()->getNextRedoLabel());
 
-  document->getUndoHistory()->doRedo();
+  document->getUndo()->doRedo();
   document->generateMaskBoundaries();
   document->destroyExtraCel(); // Regenerate extras
 
diff --git a/src/commands/cmd_reselect_mask.cpp b/src/commands/cmd_reselect_mask.cpp
index 1583f897d..d259ddd33 100644
--- a/src/commands/cmd_reselect_mask.cpp
+++ b/src/commands/cmd_reselect_mask.cpp
@@ -23,7 +23,7 @@
 #include "modules/gui.h"
 #include "raster/mask.h"
 #include "raster/sprite.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "undoers/set_mask.h"
 
 //////////////////////////////////////////////////////////////////////
@@ -60,19 +60,18 @@ bool ReselectMaskCommand::onEnabled(Context* context)
 void ReselectMaskCommand::onExecute(Context* context)
 {
   ActiveDocumentWriter document(context);
-  undo::UndoHistory* undo = document->getUndoHistory();
+  {
+    UndoTransaction undo(document, "Mask Reselection", undo::DoesntModifyDocument);
+    if (undo.isEnabled())
+      undo.pushUndoer(new undoers::SetMask(undo.getObjects(), document));
 
-  // Undo
-  if (undo->isEnabled()) {
-    undo->setLabel("Mask Reselection");
-    undo->setModification(undo::DoesntModifyDocument);
-    undo->pushUndoer(new undoers::SetMask(undo->getObjects(), document));
+    // Make the mask visible again.
+    document->setMaskVisible(true);
+
+    undo.commit();
   }
 
-  // Make the mask visible again.
-  document->setMaskVisible(true);
   document->generateMaskBoundaries();
-
   update_screen_for_document(document);
 }
 
diff --git a/src/commands/cmd_undo.cpp b/src/commands/cmd_undo.cpp
index ddb96d1ac..0159cc15e 100644
--- a/src/commands/cmd_undo.cpp
+++ b/src/commands/cmd_undo.cpp
@@ -20,10 +20,10 @@
 
 #include "app.h"
 #include "commands/command.h"
+#include "document_undo.h"
 #include "document_wrappers.h"
 #include "modules/gui.h"
 #include "raster/sprite.h"
-#include "undo/undo_history.h"
 #include "widgets/status_bar.h"
 
 class UndoCommand : public Command
@@ -49,7 +49,7 @@ bool UndoCommand::onEnabled(Context* context)
   ActiveDocumentWriter document(context);
   return
     document != NULL &&
-    document->getUndoHistory()->canUndo();
+    document->getUndo()->canUndo();
 }
 
 void UndoCommand::onExecute(Context* context)
@@ -58,9 +58,9 @@ void UndoCommand::onExecute(Context* context)
 
   app_get_statusbar()
     ->showTip(1000, "Undid %s",
-              document->getUndoHistory()->getNextUndoLabel());
+              document->getUndo()->getNextUndoLabel());
 
-  document->getUndoHistory()->doUndo();
+  document->getUndo()->doUndo();
   document->generateMaskBoundaries();
   document->destroyExtraCel(); // Regenerate extras
 
diff --git a/src/commands/filters/filter_manager_impl.cpp b/src/commands/filters/filter_manager_impl.cpp
index 594f44380..941941250 100644
--- a/src/commands/filters/filter_manager_impl.cpp
+++ b/src/commands/filters/filter_manager_impl.cpp
@@ -35,10 +35,8 @@
 #include "ui/region.h"
 #include "ui/view.h"
 #include "ui/widget.h"
-#include "undo/undo_history.h"
-#include "undoers/close_group.h"
+#include "undo_transaction.h"
 #include "undoers/image_area.h"
-#include "undoers/open_group.h"
 #include "widgets/editor/editor.h"
 
 #include <cstdlib>
@@ -206,17 +204,16 @@ void FilterManagerImpl::apply()
   }
 
   if (!cancelled) {
-    undo::UndoHistory* undo = m_document->getUndoHistory();
+    UndoTransaction undo(m_document, m_filter->getName(), undo::ModifyDocument);
 
     // Undo stuff
-    if (undo->isEnabled()) {
-      undo->setLabel(m_filter->getName());
-      undo->setModification(undo::ModifyDocument);
-      undo->pushUndoer(new undoers::ImageArea(undo->getObjects(), m_src, m_x, m_y, m_w, m_h));
-    }
+    if (undo.isEnabled())
+      undo.pushUndoer(new undoers::ImageArea(undo.getObjects(), m_src, m_x, m_y, m_w, m_h));
 
     // Copy "dst" to "src"
     image_copy(m_src, m_dst, 0, 0);
+
+    undo.commit();
   }
 }
 
@@ -234,13 +231,7 @@ void FilterManagerImpl::applyToTarget()
   // Initialize writting operation
   DocumentReader doc_reader(m_document);
   DocumentWriter doc_writer(doc_reader);
-  undo::UndoHistory* undo = m_document->getUndoHistory();
-
-  // Open group of undo operations
-  if (images.size() > 1) {
-    if (undo->isEnabled())
-      undo->pushUndoer(new undoers::OpenGroup());
-  }
+  UndoTransaction undo(m_document, m_filter->getName(), undo::ModifyDocument);
 
   m_progressBase = 0.0f;
   m_progressWidth = 1.0f / images.size();
@@ -259,11 +250,7 @@ void FilterManagerImpl::applyToTarget()
     m_progressBase += m_progressWidth;
   }
 
-  // Close group of undo operations
-  if (images.size() > 1) {
-    if (undo->isEnabled())
-      undo->pushUndoer(new undoers::CloseGroup());
-  }
+  undo.commit();
 }
 
 void FilterManagerImpl::flush()
diff --git a/src/dialogs/aniedit.cpp b/src/dialogs/aniedit.cpp
index f1a111252..447d17413 100644
--- a/src/dialogs/aniedit.cpp
+++ b/src/dialogs/aniedit.cpp
@@ -25,6 +25,7 @@
 #include "commands/params.h"
 #include "console.h"
 #include "document.h"
+#include "document_undo.h"
 #include "document_wrappers.h"
 #include "gfx/point.h"
 #include "gfx/rect.h"
@@ -35,7 +36,6 @@
 #include "skin/skin_theme.h"
 #include "ui/gui.h"
 #include "ui_context.h"
-#include "undo/undo_history.h"
 #include "undo_transaction.h"
 #include "util/celmove.h"
 #include "util/thmbnail.h"
@@ -713,11 +713,11 @@ bool AnimationEditor::onProcessMessage(Message* msg)
       // Undo.
       if (command && strcmp(command->short_name(), CommandId::Undo) == 0) {
         const DocumentReader document(const_cast<Document*>(m_document));
-        const undo::UndoHistory* undo = document->getUndoHistory();
+        const DocumentUndo* undo = document->getUndo();
 
         if (undo->canUndo()) {
           DocumentWriter document_writer(document);
-          undo::UndoHistory* undo_writer = document_writer->getUndoHistory();
+          DocumentUndo* undo_writer = document_writer->getUndo();
 
           undo_writer->doUndo();
 
@@ -732,11 +732,11 @@ bool AnimationEditor::onProcessMessage(Message* msg)
       // Redo.
       if (command && strcmp(command->short_name(), CommandId::Redo) == 0) {
         const DocumentReader document(const_cast<Document*>(m_document));
-        const undo::UndoHistory* undo = document->getUndoHistory();
+        const DocumentUndo* undo = document->getUndo();
 
         if (undo->canRedo()) {
           DocumentWriter document_writer(document);
-          undo::UndoHistory* undo_writer = document_writer->getUndoHistory();
+          DocumentUndo* undo_writer = document_writer->getUndo();
 
           undo_writer->doRedo();
 
diff --git a/src/dialogs/maskcol.cpp b/src/dialogs/maskcol.cpp
index 83e9f4c1f..a62c5a229 100644
--- a/src/dialogs/maskcol.cpp
+++ b/src/dialogs/maskcol.cpp
@@ -37,7 +37,7 @@
 #include "ui/label.h"
 #include "ui/slider.h"
 #include "ui/widget.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "undoers/set_mask.h"
 #include "util/misc.h"
 #include "widgets/color_bar.h"
@@ -139,13 +139,10 @@ void dialogs_mask_color(Document* document)
 
   if (window->get_killer() == button_ok) {
     DocumentWriter documentWriter(documentReader);
-    undo::UndoHistory* undo = document->getUndoHistory();
+    UndoTransaction undo(document, "Mask by Color", undo::DoesntModifyDocument);
 
-    if (undo->isEnabled()) {
-      undo->setLabel("Mask by Color");
-      undo->setModification(undo::DoesntModifyDocument);
-      undo->pushUndoer(new undoers::SetMask(undo->getObjects(), document));
-    }
+    if (undo.isEnabled())
+      undo.pushUndoer(new undoers::SetMask(undo.getObjects(), document));
 
     // Change the mask
     {
@@ -153,6 +150,8 @@ void dialogs_mask_color(Document* document)
       document->setMask(mask);
     }
 
+    undo.commit();
+
     set_config_color("MaskColor", "Color", button_color->getColor());
     set_config_int("MaskColor", "Tolerance", slider_tolerance->getValue());
     set_config_bool("MaskColor", "Preview", check_preview->isSelected());
diff --git a/src/document.cpp b/src/document.cpp
index f8e05e3cf..82a714628 100644
--- a/src/document.cpp
+++ b/src/document.cpp
@@ -24,29 +24,23 @@
 #include "base/mutex.h"
 #include "base/scoped_lock.h"
 #include "base/unique_ptr.h"
+#include "document_undo.h"
 #include "file/format_options.h"
 #include "flatten.h"
-#include "objects_container_impl.h"
 #include "raster/cel.h"
 #include "raster/layer.h"
 #include "raster/mask.h"
 #include "raster/palette.h"
 #include "raster/sprite.h"
 #include "raster/stock.h"
-#include "undo/undo_history.h"
 #include "undoers/add_image.h"
 #include "undoers/add_layer.h"
 #include "util/boundary.h"
 
-#include <allegro/config.h>     // TODO remove this when get_config_int() is removed from here
-
-using namespace undo;
-
 Document::Document(Sprite* sprite)
   : m_id(WithoutDocumentId)
   , m_sprite(sprite)
-  , m_objects(new ObjectsContainerImpl)
-  , m_undoHistory(new UndoHistory(m_objects, this))
+  , m_undo(new DocumentUndo)
   , m_filename("Sprite")
   , m_associated_to_file(false)
   , m_mutex(new Mutex)
@@ -147,7 +141,7 @@ void Document::setFilename(const char* filename)
 
 bool Document::isModified() const
 {
-  return !m_undoHistory->isSavedState();
+  return !m_undo->isSavedState();
 }
 
 bool Document::isAssociatedToFile() const
@@ -157,7 +151,7 @@ bool Document::isAssociatedToFile() const
 
 void Document::markAsSaved()
 {
-  m_undoHistory->markSavedState();
+  m_undo->markSavedState();
   m_associated_to_file = true;
 }
 
@@ -324,7 +318,7 @@ void Document::resetTransformation()
 
 void Document::copyLayerContent(const Layer* sourceLayer0, Document* destDoc, Layer* destLayer0) const
 {
-  UndoHistory* undo = destDoc->getUndoHistory();
+  DocumentUndo* undo = destDoc->getUndo();
 
   // Copy the layer name
   destLayer0->setName(sourceLayer0->getName());
@@ -429,7 +423,7 @@ Document* Document::duplicate(DuplicateType type) const
 
     case DuplicateExactCopy:
       // Disable the undo
-      documentCopy->getUndoHistory()->setEnabled(false);
+      documentCopy->getUndo()->setEnabled(false);
 
       // Copy the layer folder
       copyLayerContent(getSprite()->getFolder(), documentCopy, spriteCopy->getFolder());
@@ -441,7 +435,7 @@ Document* Document::duplicate(DuplicateType type) const
       }
 
       // Re-enable the undo
-      documentCopy->getUndoHistory()->setEnabled(true);
+      documentCopy->getUndo()->setEnabled(true);
       break;
 
     case DuplicateWithFlattenLayers:
@@ -547,8 +541,3 @@ void Document::unlock()
     ASSERT(false);
   }
 }
-
-size_t Document::getUndoSizeLimit()
-{
-  return ((size_t)get_config_int("Options", "UndoSizeLimit", 8))*1024*1024;
-}
diff --git a/src/document.h b/src/document.h
index 961242609..efc32c4f3 100644
--- a/src/document.h
+++ b/src/document.h
@@ -19,18 +19,17 @@
 #ifndef DOCUMENT_H_INCLUDED
 #define DOCUMENT_H_INCLUDED
 
-#include "base/compiler_specific.h"
 #include "base/disable_copying.h"
 #include "base/shared_ptr.h"
 #include "base/unique_ptr.h"
 #include "document_id.h"
 #include "gfx/transformation.h"
 #include "raster/pixel_format.h"
-#include "undo/undo_config_provider.h"
 
 #include <string>
 
 class Cel;
+class DocumentUndo;
 class FormatOptions;
 class Image;
 class Layer;
@@ -39,11 +38,6 @@ class Mutex;
 class Sprite;
 struct _BoundSeg;
 
-namespace undo {
-  class ObjectsContainer;
-  class UndoHistory;
-}
-
 struct PreferredEditorSettings
 {
   int scroll_x;
@@ -60,7 +54,7 @@ enum DuplicateType
 
 // An application document. It is the class used to contain one file
 // opened and being edited by the user (a sprite).
-class Document : public undo::UndoConfigProvider
+class Document
 {
 public:
 
@@ -83,10 +77,10 @@ public:
   void setId(DocumentId id) { m_id = id; }
 
   const Sprite* getSprite() const { return m_sprite; }
-  const undo::UndoHistory* getUndoHistory() const { return m_undoHistory; }
+  const DocumentUndo* getUndo() const { return m_undo; }
 
   Sprite* getSprite() { return m_sprite; }
-  undo::UndoHistory* getUndoHistory() { return m_undoHistory; }
+  DocumentUndo* getUndo() { return m_undo; }
 
   void addSprite(Sprite* sprite);
 
@@ -180,23 +174,14 @@ public:
   void unlock();
 
 private:
-  size_t getUndoSizeLimit() OVERRIDE;
-
   // Unique identifier for this document (it is assigned by Documents class).
   DocumentId m_id;
 
   // The main sprite.
   UniquePtr<Sprite> m_sprite;
 
-  // Collection of objects used by UndoHistory to reference deleted
-  // objects that are re-created by an Undoer. The container keeps an
-  // ID that is saved in the serialization process, and loaded in the
-  // deserialization process. The ID can be used by different undoers
-  // to keep references to deleted objects.
-  UniquePtr<undo::ObjectsContainer> m_objects;
-
-  // Stack of undoers to undo operations.
-  UniquePtr<undo::UndoHistory> m_undoHistory;
+  // Undo and redo information about the document.
+  UniquePtr<DocumentUndo> m_undo;
 
   // Document's file name (from where it was loaded, where it is saved).
   std::string m_filename;
diff --git a/src/document_undo.cpp b/src/document_undo.cpp
new file mode 100644
index 000000000..f2b708b99
--- /dev/null
+++ b/src/document_undo.cpp
@@ -0,0 +1,127 @@
+/* ASEPRITE
+ * Copyright (C) 2001-2012  David Capello
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "config.h"
+
+#include "document_undo.h"
+
+#include "objects_container_impl.h"
+#include "undo/undo_history.h"
+#include "undoers/close_group.h"
+
+#include <allegro/config.h>     // TODO remove this when get_config_int() is removed from here
+#include <cassert>
+
+DocumentUndo::DocumentUndo()
+  : m_objects(new ObjectsContainerImpl)
+  , m_undoHistory(new undo::UndoHistory(m_objects, this))
+  , m_enabled(true)
+{
+}
+
+
+bool DocumentUndo::canUndo() const
+{
+  return m_undoHistory->canUndo();
+}
+
+bool DocumentUndo::canRedo() const
+{
+  return m_undoHistory->canRedo();
+}
+
+void DocumentUndo::doUndo()
+{
+  return m_undoHistory->doUndo();
+}
+
+void DocumentUndo::doRedo()
+{
+  return m_undoHistory->doRedo();
+}
+
+void DocumentUndo::clearRedo()
+{
+  return m_undoHistory->clearRedo();
+}
+
+bool DocumentUndo::isSavedState() const
+{
+  return m_undoHistory->isSavedState();
+}
+
+void DocumentUndo::markSavedState()
+{
+  return m_undoHistory->markSavedState();
+}
+
+undo::ObjectsContainer* DocumentUndo::getObjects() const
+{
+  return m_undoHistory->getObjects();
+}
+
+void DocumentUndo::pushUndoer(undo::Undoer* undoer)
+{
+  return m_undoHistory->pushUndoer(undoer);
+}
+
+bool DocumentUndo::implantUndoerInLastGroup(undo::Undoer* undoer)
+{
+  return m_undoHistory->implantUndoerInLastGroup(undoer);
+}
+
+size_t DocumentUndo::getUndoSizeLimit()
+{
+  return ((size_t)get_config_int("Options", "UndoSizeLimit", 8))*1024*1024;
+}
+
+const char* DocumentUndo::getNextUndoLabel() const
+{
+  undo::Undoer* undoer = m_undoHistory->getNextUndoer();
+  if (undoer) {
+    if (undoers::CloseGroup* closeGroup = dynamic_cast<undoers::CloseGroup*>(undoer)) {
+      return closeGroup->getLabel();
+    }
+    else {
+      assert(false && "There are some action without a CloseGroup");
+      return "";
+    }
+  }
+  else {
+    assert(false && "There are some action without label");
+    return "";
+  }
+}
+
+const char* DocumentUndo::getNextRedoLabel() const
+{
+  undo::Undoer* undoer = m_undoHistory->getNextRedoer();
+  if (undoer) {
+    if (undoers::CloseGroup* closeGroup = dynamic_cast<undoers::CloseGroup*>(undoer)) {
+      return closeGroup->getLabel();
+    }
+    else {
+      assert(false && "There are some action without a CloseGroup");
+      return "";
+    }
+  }
+  else {
+    assert(false && "There are some action without label");
+    return "";
+  }
+}
diff --git a/src/document_undo.h b/src/document_undo.h
new file mode 100644
index 000000000..3ad027fa5
--- /dev/null
+++ b/src/document_undo.h
@@ -0,0 +1,79 @@
+/* ASEPRITE
+ * Copyright (C) 2001-2012  David Capello
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef DOCUMENT_UNDO_H_INCLUDED
+#define DOCUMENT_UNDO_H_INCLUDED
+
+#include "base/compiler_specific.h"
+#include "base/disable_copying.h"
+#include "base/unique_ptr.h"
+#include "undo/undo_config_provider.h"
+
+namespace undo {
+  class ObjectsContainer;
+  class UndoHistory;
+  class Undoer;
+}
+
+class DocumentUndo : public undo::UndoConfigProvider
+{
+public:
+  DocumentUndo();
+
+  bool isEnabled() const { return m_enabled; }
+  void setEnabled(bool state) { m_enabled = state; }
+
+  bool canUndo() const;
+  bool canRedo() const;
+
+  void doUndo();
+  void doRedo();
+
+  void clearRedo();
+
+  bool isSavedState() const;
+  void markSavedState();
+
+  undo::ObjectsContainer* getObjects() const;
+
+  void pushUndoer(undo::Undoer* undoer);
+
+  bool implantUndoerInLastGroup(undo::Undoer* undoer);
+
+  const char* getNextUndoLabel() const;
+  const char* getNextRedoLabel() const;
+
+private:
+  size_t getUndoSizeLimit() OVERRIDE;
+
+  // Collection of objects used by UndoHistory to reference deleted
+  // objects that are re-created by an Undoer. The container keeps an
+  // ID that is saved in the serialization process, and loaded in the
+  // deserialization process. The ID can be used by different undoers
+  // to keep references to deleted objects.
+  UniquePtr<undo::ObjectsContainer> m_objects;
+
+  // Stack of undoers to undo operations.
+  UniquePtr<undo::UndoHistory> m_undoHistory;
+
+  bool m_enabled;
+
+  DISABLE_COPYING(DocumentUndo);
+};
+
+#endif
diff --git a/src/tools/inks.h b/src/tools/inks.h
index b114f18f1..5442d2e8a 100644
--- a/src/tools/inks.h
+++ b/src/tools/inks.h
@@ -22,8 +22,8 @@
 #include "app/color_utils.h"
 #include "context.h"
 #include "document.h"
+#include "document_undo.h"
 #include "raster/mask.h"
-#include "undo/undo_history.h"
 #include "undoers/set_mask.h"
 
 
@@ -261,7 +261,7 @@ public:
     m_modify_selection = state;
 
     if (state) {
-      undo::UndoHistory* undo = loop->getDocument()->getUndoHistory();
+      DocumentUndo* undo = loop->getDocument()->getUndo();
       if (undo->isEnabled())
         undo->pushUndoer(new undoers::SetMask(undo->getObjects(), loop->getDocument()));
 
diff --git a/src/undo/undo_history.cpp b/src/undo/undo_history.cpp
index 5f5d8c83f..7922a4ec9 100644
--- a/src/undo/undo_history.cpp
+++ b/src/undo/undo_history.cpp
@@ -24,9 +24,6 @@ UndoHistory::UndoHistory(ObjectsContainer* objects, UndoConfigProvider* configPr
   m_groupLevel = 0;
   m_diffCount = 0;
   m_diffSaved = 0;
-  m_enabled = true;
-  m_label = NULL;
-  m_modification = ModifyDocument;
 
   m_undoers = new UndoersStack(this);
   try {
@@ -44,16 +41,6 @@ UndoHistory::~UndoHistory()
   delete m_redoers;
 }
 
-bool UndoHistory::isEnabled() const
-{
-  return m_enabled ? true: false;
-}
-
-void UndoHistory::setEnabled(bool state)
-{
-  m_enabled = state;
-}
-
 bool UndoHistory::canUndo() const
 {
   return !m_undoers->empty();
@@ -87,40 +74,20 @@ void UndoHistory::clearRedo()
     m_diffSaved = -1;
 }
 
-const char* UndoHistory::getLabel()
+Undoer* UndoHistory::getNextUndoer()
 {
-  return m_label;
+  if (!m_undoers->empty())
+    return *m_undoers->begin();
+  else
+    return NULL;
 }
 
-void UndoHistory::setLabel(const char* label)
+Undoer* UndoHistory::getNextRedoer()
 {
-  m_label = label;
-}
-
-Modification UndoHistory::getModification()
-{
-  return m_modification;
-}
-
-void UndoHistory::setModification(Modification mod)
-{
-  m_modification = mod;
-}
-
-const char* UndoHistory::getNextUndoLabel() const
-{
-  ASSERT(canUndo());
-
-  UndoersStack::Item* item = *m_undoers->begin();
-  return item->getLabel();
-}
-
-const char* UndoHistory::getNextRedoLabel() const
-{
-  ASSERT(canRedo());
-
-  UndoersStack::Item* item = *m_redoers->begin();
-  return item->getLabel();
+  if (!m_redoers->empty())
+    return *m_redoers->begin();
+  else
+    return NULL;
 }
 
 bool UndoHistory::isSavedState() const
@@ -141,20 +108,13 @@ void UndoHistory::runUndo(Direction direction)
 
   do {
     const char* itemLabel = NULL;
-    Modification itemModification = DoesntModifyDocument;
-
-    if (!undoers->empty()) {
-      UndoersStack::Item* item = *undoers->begin();
-      itemLabel = item->getLabel();
-      itemModification = item->getModification();
-    }
 
     Undoer* undoer = undoers->popUndoer(UndoersStack::PopFromHead);
     if (!undoer)
       break;
 
-    setLabel(itemLabel);
-    setModification(itemModification);
+    Modification itemModification = DoesntModifyDocument;
+    itemModification = undoer->getModification();
 
     undoer->revert(getObjects(), redoers);
 
@@ -202,7 +162,7 @@ void UndoHistory::pushUndoer(Undoer* undoer)
   postUndoerAddedEvent(undoer);
 }
 
-bool UndoHistory::graftUndoerInLastGroup(Undoer* undoer)
+bool UndoHistory::implantUndoerInLastGroup(Undoer* undoer)
 {
   Undoer* lastUndoer = m_undoers->popUndoer(UndoersStack::PopFromHead);
   bool result;
@@ -241,7 +201,7 @@ void UndoHistory::postUndoerAddedEvent(Undoer* undoer)
   // it has passed the undo-limit.
   if (m_groupLevel == 0) {
     // More differences.
-    if (m_modification == ModifyDocument)
+    if (undoer->getModification() == ModifyDocument)
       m_diffCount++;
 
     checkSizeLimit();
diff --git a/src/undo/undo_history.h b/src/undo/undo_history.h
index 506e7296a..1820e4bfd 100644
--- a/src/undo/undo_history.h
+++ b/src/undo/undo_history.h
@@ -24,9 +24,6 @@ public:
   UndoHistory(ObjectsContainer* objects, UndoConfigProvider* configProvider);
   virtual ~UndoHistory();
 
-  bool isEnabled() const;
-  void setEnabled(bool state);
-
   bool canUndo() const;
   bool canRedo() const;
 
@@ -35,18 +32,8 @@ public:
 
   void clearRedo();
 
-  // Current label for next added Undoers.
-  const char* getLabel();
-  void setLabel(const char* label);
-
-  // Change the "modify saved status" flag to be assigned for next
-  // added items. When it is activated means that each added Undoer
-  // modifies the "saved status" of the document.
-  Modification getModification();
-  void setModification(Modification mod);
-
-  const char* getNextUndoLabel() const;
-  const char* getNextRedoLabel() const;
+  Undoer* getNextUndoer();
+  Undoer* getNextRedoer();
 
   bool isSavedState() const;
   void markSavedState();
@@ -58,7 +45,7 @@ public:
 
   // Special method to add new undoers inside the last added group.
   // Returns true if the undoer was added in a group.
-  bool graftUndoerInLastGroup(Undoer* undoer);
+  bool implantUndoerInLastGroup(Undoer* undoer);
 
 private:
   enum Direction { UndoDirection, RedoDirection };
@@ -76,9 +63,6 @@ private:
   int m_groupLevel;
   int m_diffCount;
   int m_diffSaved;
-  bool m_enabled;               // Is undo enabled?
-  const char* m_label;          // Current label to be applied to all next undo operations.
-  Modification m_modification;  // Current label to be applied to all next undo operations.
   UndoConfigProvider* m_configProvider;
 };
 
diff --git a/src/undo/undoer.h b/src/undo/undoer.h
index e6db08992..649b31257 100644
--- a/src/undo/undoer.h
+++ b/src/undo/undoer.h
@@ -7,6 +7,8 @@
 #ifndef UNDO_UNDOER_H_INCLUDED
 #define UNDO_UNDOER_H_INCLUDED
 
+#include "undo/modification.h"
+
 namespace undo {
 
 class ObjectsContainer;
@@ -30,6 +32,10 @@ public:
   // using to revert the action.
   virtual size_t getMemSize() const = 0;
 
+  // Returns the kind of modification that this item does with the
+  // document.
+  virtual Modification getModification() const = 0;
+
   // Returns true if this undoer is the first action of a group.
   virtual bool isOpenGroup() const = 0;
 
diff --git a/src/undo/undoers_stack.cpp b/src/undo/undoers_stack.cpp
index afd429927..10975efbe 100644
--- a/src/undo/undoers_stack.cpp
+++ b/src/undo/undoers_stack.cpp
@@ -26,10 +26,8 @@ UndoersStack::~UndoersStack()
 
 void UndoersStack::clear()
 {
-  for (iterator it = begin(), end = this->end(); it != end; ++it) {
-    (*it)->getUndoer()->dispose(); // Delete the Undoer.
-    delete *it;                    // Delete the UndoersStack::Item.
-  }
+  for (iterator it = begin(), end = this->end(); it != end; ++it)
+    (*it)->dispose();           // Delete the Undoer.
 
   m_size = 0;
   m_items.clear();              // Clear the list of items.
@@ -50,15 +48,7 @@ void UndoersStack::pushUndoer(Undoer* undoer)
   ASSERT(undoer != NULL);
 
   try {
-    Item* item = new Item(m_undoHistory->getLabel(),
-                          m_undoHistory->getModification(), undoer);
-    try {
-      m_items.insert(begin(), item);
-    }
-    catch (...) {
-      delete item;
-      throw;
-    }
+    m_items.insert(begin(), undoer);
   }
   catch (...) {
     undoer->dispose();
@@ -79,8 +69,7 @@ Undoer* UndoersStack::popUndoer(PopFrom popFrom)
     else
       it = --end();
 
-    undoer = (*it)->getUndoer();    // Set the undoer to return.
-    delete *it;                     // Delete the UndoersStack::Item.
+    undoer = (*it);                 // Set the undoer to return.
     m_items.erase(it);              // Erase the item from the stack.
     m_size -= undoer->getMemSize(); // Reduce the stack size.
   }
@@ -100,7 +89,7 @@ size_t UndoersStack::countUndoGroups() const
     level = 0;
 
     do {
-      const Undoer* undoer = (*it)->getUndoer();
+      const Undoer* undoer = (*it);
       ++it;
 
       if (undoer->isOpenGroup())
diff --git a/src/undo/undoers_stack.h b/src/undo/undoers_stack.h
index 490de20de..822b3b703 100644
--- a/src/undo/undoers_stack.h
+++ b/src/undo/undoers_stack.h
@@ -7,7 +7,6 @@
 #ifndef UNDO_UNDOERS_STACK_H_INCLUDED
 #define UNDO_UNDOERS_STACK_H_INCLUDED
 
-#include "undo/modification.h"
 #include "undo/undoers_collector.h"
 
 #include <vector>
@@ -29,26 +28,7 @@ public:
     PopFromTail
   };
 
-  // One item in the stack (label + Undoer)
-  class Item
-  {
-  public:
-    Item(const char* label, Modification mod, Undoer* undoer)
-      : m_label(label)
-      , m_mod(mod)
-      , m_undoer(undoer) { }
-
-    const char* getLabel() const { return m_label; }
-    Modification getModification() const { return m_mod; }
-    Undoer* getUndoer() const { return m_undoer; }
-
-  private:
-    const char* m_label;
-    Modification m_mod;
-    Undoer* m_undoer;
-  };
-
-  typedef std::vector<Item*> Items;
+  typedef std::vector<Undoer*> Items;
   typedef Items::iterator iterator;
   typedef Items::const_iterator const_iterator;
 
diff --git a/src/undo_transaction.cpp b/src/undo_transaction.cpp
index 30583b376..99cdef5a4 100644
--- a/src/undo_transaction.cpp
+++ b/src/undo_transaction.cpp
@@ -22,6 +22,7 @@
 
 #include "base/unique_ptr.h"
 #include "document.h"
+#include "document_undo.h"
 #include "raster/algorithm/flip_image.h"
 #include "raster/blend.h"
 #include "raster/cel.h"
@@ -64,21 +65,20 @@
 #include "undoers/set_total_frames.h"
 
 UndoTransaction::UndoTransaction(Document* document, const char* label, undo::Modification modification)
+  : m_label(label)
+  , m_modification(modification)
 {
   ASSERT(label != NULL);
 
   m_document = document;
   m_sprite = document->getSprite();
-  m_undoHistory = document->getUndoHistory();
+  m_undo = document->getUndo();
   m_closed = false;
   m_committed = false;
-  m_enabledFlag = m_undoHistory->isEnabled();
+  m_enabledFlag = m_undo->isEnabled();
 
-  if (isEnabled()) {
-    m_undoHistory->setLabel(label);
-    m_undoHistory->setModification(modification);
-    m_undoHistory->pushUndoer(new undoers::OpenGroup());
-  }
+  if (isEnabled())
+    m_undo->pushUndoer(new undoers::OpenGroup(m_label, m_modification));
 }
 
 UndoTransaction::~UndoTransaction()
@@ -106,7 +106,7 @@ void UndoTransaction::closeUndoGroup()
 
   if (isEnabled()) {
     // Close the undo information.
-    m_undoHistory->pushUndoer(new undoers::CloseGroup());
+    m_undo->pushUndoer(new undoers::CloseGroup(m_label, m_modification));
     m_closed = true;
   }
 }
@@ -132,21 +132,31 @@ void UndoTransaction::rollback()
     closeUndoGroup();
 
     // Undo the group of operations.
-    m_undoHistory->doUndo();
+    m_undo->doUndo();
 
     // Clear the redo (sorry to the user, here we lost the old redo
     // information).
-    m_undoHistory->clearRedo();
+    m_undo->clearRedo();
   }
 }
 
+void UndoTransaction::pushUndoer(undo::Undoer* undoer)
+{
+  m_undo->pushUndoer(undoer);
+}
+
+undo::ObjectsContainer* UndoTransaction::getObjects() const
+{
+  return m_undo->getObjects();
+}
+
 void UndoTransaction::setNumberOfFrames(int frames)
 {
   ASSERT(frames >= 1);
 
   // Save in undo the current totalFrames property
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetTotalFrames(m_undoHistory->getObjects(), m_sprite));
+    m_undo->pushUndoer(new undoers::SetTotalFrames(m_undo->getObjects(), m_sprite));
 
   // Change the property
   m_sprite->setTotalFrames(frames);
@@ -157,7 +167,7 @@ void UndoTransaction::setCurrentFrame(int frame)
   ASSERT(frame >= 0);
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetCurrentFrame(m_undoHistory->getObjects(), m_sprite));
+    m_undo->pushUndoer(new undoers::SetCurrentFrame(m_undo->getObjects(), m_sprite));
 
   m_sprite->setCurrentFrame(frame);
 }
@@ -171,8 +181,8 @@ void UndoTransaction::setCurrentFrame(int frame)
 void UndoTransaction::setCurrentLayer(Layer* layer)
 {
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetCurrentLayer(
-        m_undoHistory->getObjects(), m_sprite));
+    m_undo->pushUndoer(new undoers::SetCurrentLayer(
+        m_undo->getObjects(), m_sprite));
 
   m_sprite->setCurrentLayer(layer);
 }
@@ -183,7 +193,7 @@ void UndoTransaction::setSpriteSize(int w, int h)
   ASSERT(h > 0);
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetSpriteSize(m_undoHistory->getObjects(), m_sprite));
+    m_undo->pushUndoer(new undoers::SetSpriteSize(m_undo->getObjects(), m_sprite));
 
   m_sprite->setSize(w, h);
 }
@@ -242,7 +252,7 @@ void UndoTransaction::setPixelFormat(PixelFormat newFormat, DitheringMethod dith
 
   // Change pixel format of the stock of images.
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetStockPixelFormat(m_undoHistory->getObjects(), m_sprite->getStock()));
+    m_undo->pushUndoer(new undoers::SetStockPixelFormat(m_undo->getObjects(), m_sprite->getStock()));
 
   m_sprite->getStock()->setPixelFormat(newFormat);
 
@@ -264,7 +274,7 @@ void UndoTransaction::setPixelFormat(PixelFormat newFormat, DitheringMethod dith
 
   // Change sprite's pixel format.
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetSpritePixelFormat(m_undoHistory->getObjects(), m_sprite));
+    m_undo->pushUndoer(new undoers::SetSpritePixelFormat(m_undo->getObjects(), m_sprite));
 
   m_sprite->setPixelFormat(newFormat);
 
@@ -280,12 +290,12 @@ void UndoTransaction::setPixelFormat(PixelFormat newFormat, DitheringMethod dith
       PalettesList palettes = m_sprite->getPalettes();
       for (PalettesList::iterator it = palettes.begin(); it != palettes.end(); ++it) {
         Palette* palette = *it;
-        m_undoHistory->pushUndoer(new undoers::RemovePalette(
-            m_undoHistory->getObjects(), m_sprite, palette->getFrame()));
+        m_undo->pushUndoer(new undoers::RemovePalette(
+            m_undo->getObjects(), m_sprite, palette->getFrame()));
       }
 
-      m_undoHistory->pushUndoer(new undoers::AddPalette(
-        m_undoHistory->getObjects(), m_sprite, 0));
+      m_undo->pushUndoer(new undoers::AddPalette(
+        m_undo->getObjects(), m_sprite, 0));
     }
 
     // It's a UniquePtr because setPalette'll create a copy of "graypal".
@@ -310,7 +320,7 @@ int UndoTransaction::addImageInStock(Image* image)
   int image_index = m_sprite->getStock()->addImage(image);
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::AddImage(m_undoHistory->getObjects(),
+    m_undo->pushUndoer(new undoers::AddImage(m_undo->getObjects(),
         m_sprite->getStock(), image_index));
 
   return image_index;
@@ -327,7 +337,7 @@ void UndoTransaction::removeImageFromStock(int image_index)
   ASSERT(image);
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::RemoveImage(m_undoHistory->getObjects(),
+    m_undo->pushUndoer(new undoers::RemoveImage(m_undo->getObjects(),
         m_sprite->getStock(), image_index));
 
   m_sprite->getStock()->removeImage(image);
@@ -342,7 +352,7 @@ void UndoTransaction::replaceStockImage(int image_index, Image* new_image)
 
   // replace the image in the stock
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::ReplaceImage(m_undoHistory->getObjects(),
+    m_undo->pushUndoer(new undoers::ReplaceImage(m_undo->getObjects(),
         m_sprite->getStock(), image_index));
 
   m_sprite->getStock()->replaceImage(image_index, new_image);
@@ -361,7 +371,7 @@ LayerImage* UndoTransaction::newLayer()
 
   // add the layer in the sprite set
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::AddLayer(m_undoHistory->getObjects(),
+    m_undo->pushUndoer(new undoers::AddLayer(m_undo->getObjects(),
         m_sprite->getFolder(), layer));
 
   m_sprite->getFolder()->add_layer(layer);
@@ -400,7 +410,7 @@ void UndoTransaction::removeLayer(Layer* layer)
 
   // remove the layer
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::RemoveLayer(m_undoHistory->getObjects(),
+    m_undo->pushUndoer(new undoers::RemoveLayer(m_undo->getObjects(),
         layer));
 
   parent->remove_layer(layer);
@@ -412,7 +422,7 @@ void UndoTransaction::removeLayer(Layer* layer)
 void UndoTransaction::moveLayerAfter(Layer* layer, Layer* after_this)
 {
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::MoveLayer(m_undoHistory->getObjects(), layer));
+    m_undo->pushUndoer(new undoers::MoveLayer(m_undo->getObjects(), layer));
 
   layer->get_parent()->move_layer(layer, after_this);
 }
@@ -501,7 +511,7 @@ void UndoTransaction::backgroundFromLayer(LayerImage* layer, int bgcolor)
     if (bg_image->w == cel_image->w &&
         bg_image->h == cel_image->h) {
       if (isEnabled())
-        m_undoHistory->pushUndoer(new undoers::ImageArea(m_undoHistory->getObjects(),
+        m_undo->pushUndoer(new undoers::ImageArea(m_undo->getObjects(),
             cel_image, 0, 0, cel_image->w, cel_image->h));
 
       image_copy(cel_image, bg_image, 0, 0);
@@ -540,8 +550,8 @@ void UndoTransaction::layerFromBackground()
   ASSERT(m_sprite->getCurrentLayer()->is_background());
 
   if (isEnabled()) {
-    m_undoHistory->pushUndoer(new undoers::SetLayerFlags(m_undoHistory->getObjects(), m_sprite->getCurrentLayer()));
-    m_undoHistory->pushUndoer(new undoers::SetLayerName(m_undoHistory->getObjects(), m_sprite->getCurrentLayer()));
+    m_undo->pushUndoer(new undoers::SetLayerFlags(m_undo->getObjects(), m_sprite->getCurrentLayer()));
+    m_undo->pushUndoer(new undoers::SetLayerName(m_undo->getObjects(), m_sprite->getCurrentLayer()));
   }
 
   m_sprite->getCurrentLayer()->set_background(false);
@@ -568,13 +578,13 @@ void UndoTransaction::flattenLayers(int bgcolor)
     background = new LayerImage(m_sprite);
 
     if (isEnabled())
-      m_undoHistory->pushUndoer(new undoers::AddLayer(m_undoHistory->getObjects(),
+      m_undo->pushUndoer(new undoers::AddLayer(m_undo->getObjects(),
           m_sprite->getFolder(), background));
 
     m_sprite->getFolder()->add_layer(background);
 
     if (isEnabled())
-      m_undoHistory->pushUndoer(new undoers::MoveLayer(m_undoHistory->getObjects(),
+      m_undo->pushUndoer(new undoers::MoveLayer(m_undo->getObjects(),
           background));
 
     background->configureAsBackground();
@@ -595,8 +605,8 @@ void UndoTransaction::flattenLayers(int bgcolor)
       if (isEnabled()) {
         Dirty* dirty = new Dirty(cel_image, image);
         dirty->saveImagePixels(cel_image);
-        m_undoHistory->pushUndoer(new undoers::DirtyArea(
-            m_undoHistory->getObjects(), cel_image, dirty));
+        m_undo->pushUndoer(new undoers::DirtyArea(
+            m_undo->getObjects(), cel_image, dirty));
         delete dirty;
       }
     }
@@ -620,8 +630,8 @@ void UndoTransaction::flattenLayers(int bgcolor)
   /* select the background */
   if (m_sprite->getCurrentLayer() != background) {
     if (isEnabled())
-      m_undoHistory->pushUndoer(new undoers::SetCurrentLayer(
-          m_undoHistory->getObjects(), m_sprite));
+      m_undo->pushUndoer(new undoers::SetCurrentLayer(
+          m_undo->getObjects(), m_sprite));
 
     m_sprite->setCurrentLayer(background);
   }
@@ -637,7 +647,7 @@ void UndoTransaction::flattenLayers(int bgcolor)
 
       // Remove the layer
       if (isEnabled())
-        m_undoHistory->pushUndoer(new undoers::RemoveLayer(m_undoHistory->getObjects(),
+        m_undo->pushUndoer(new undoers::RemoveLayer(m_undo->getObjects(),
             old_layer));
 
       m_sprite->getFolder()->remove_layer(old_layer);
@@ -651,9 +661,9 @@ void UndoTransaction::flattenLayers(int bgcolor)
 void UndoTransaction::configureLayerAsBackground(LayerImage* layer)
 {
   if (isEnabled()) {
-    m_undoHistory->pushUndoer(new undoers::SetLayerFlags(m_undoHistory->getObjects(), layer));
-    m_undoHistory->pushUndoer(new undoers::SetLayerName(m_undoHistory->getObjects(), layer));
-    m_undoHistory->pushUndoer(new undoers::MoveLayer(m_undoHistory->getObjects(), layer));
+    m_undo->pushUndoer(new undoers::SetLayerFlags(m_undo->getObjects(), layer));
+    m_undo->pushUndoer(new undoers::SetLayerName(m_undo->getObjects(), layer));
+    m_undo->pushUndoer(new undoers::MoveLayer(m_undo->getObjects(), layer));
   }
 
   layer->configureAsBackground();
@@ -787,7 +797,7 @@ void UndoTransaction::addCel(LayerImage* layer, Cel* cel)
   ASSERT(cel);
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::AddCel(m_undoHistory->getObjects(),
+    m_undo->pushUndoer(new undoers::AddCel(m_undo->getObjects(),
         layer, cel));
 
   layer->addCel(cel);
@@ -815,7 +825,7 @@ void UndoTransaction::removeCel(LayerImage* layer, Cel* cel)
     removeImageFromStock(cel->getImage());
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::RemoveCel(m_undoHistory->getObjects(),
+    m_undo->pushUndoer(new undoers::RemoveCel(m_undo->getObjects(),
         layer, cel));
 
   // remove the cel from the layer
@@ -831,7 +841,7 @@ void UndoTransaction::setCelFramePosition(Cel* cel, int frame)
   ASSERT(frame >= 0);
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetCelFrame(m_undoHistory->getObjects(), cel));
+    m_undo->pushUndoer(new undoers::SetCelFrame(m_undo->getObjects(), cel));
 
   cel->setFrame(frame);
 }
@@ -841,7 +851,7 @@ void UndoTransaction::setCelPosition(Cel* cel, int x, int y)
   ASSERT(cel);
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetCelPosition(m_undoHistory->getObjects(), cel));
+    m_undo->pushUndoer(new undoers::SetCelPosition(m_undo->getObjects(), cel));
 
   cel->setPosition(x, y);
 }
@@ -849,8 +859,8 @@ void UndoTransaction::setCelPosition(Cel* cel, int x, int y)
 void UndoTransaction::setFrameDuration(int frame, int msecs)
 {
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetFrameDuration(
-        m_undoHistory->getObjects(), m_sprite, frame));
+    m_undo->pushUndoer(new undoers::SetFrameDuration(
+        m_undo->getObjects(), m_sprite, frame));
 
   m_sprite->setFrameDuration(frame, msecs);
 }
@@ -859,8 +869,8 @@ void UndoTransaction::setConstantFrameRate(int msecs)
 {
   if (isEnabled()) {
     for (int fr=0; fr<m_sprite->getTotalFrames(); ++fr)
-      m_undoHistory->pushUndoer(new undoers::SetFrameDuration(
-          m_undoHistory->getObjects(), m_sprite, fr));
+      m_undo->pushUndoer(new undoers::SetFrameDuration(
+          m_undo->getObjects(), m_sprite, fr));
   }
 
   m_sprite->setDurationForAllFrames(msecs);
@@ -1000,7 +1010,7 @@ void UndoTransaction::clearMask(int bgcolor)
     // If the layer is the background then we clear the image.
     if (m_sprite->getCurrentLayer()->is_background()) {
       if (isEnabled())
-        m_undoHistory->pushUndoer(new undoers::ImageArea(m_undoHistory->getObjects(),
+        m_undo->pushUndoer(new undoers::ImageArea(m_undo->getObjects(),
             image, 0, 0, image->w, image->h));
 
       // clear all
@@ -1026,7 +1036,7 @@ void UndoTransaction::clearMask(int bgcolor)
       return;
 
     if (isEnabled())
-      m_undoHistory->pushUndoer(new undoers::ImageArea(m_undoHistory->getObjects(),
+      m_undo->pushUndoer(new undoers::ImageArea(m_undo->getObjects(),
           image, x1, y1, x2-x1+1, y2-y1+1));
 
     // clear the masked zones
@@ -1053,9 +1063,9 @@ void UndoTransaction::flipImage(Image* image,
 {
   // Insert the undo operation.
   if (isEnabled()) {
-    m_undoHistory->pushUndoer
+    m_undo->pushUndoer
       (new undoers::FlipImage
-       (m_undoHistory->getObjects(), image, bounds, flipType));
+       (m_undo->getObjects(), image, bounds, flipType));
   }
 
   // Flip the portion of the bitmap.
@@ -1074,7 +1084,7 @@ void UndoTransaction::flipImageWithMask(Image* image, const Mask* mask, raster::
     UniquePtr<Dirty> dirty((new Dirty(image, flippedImage)));
     dirty->saveImagePixels(image);
 
-    m_undoHistory->pushUndoer(new undoers::DirtyArea(m_undoHistory->getObjects(), image, dirty));
+    m_undo->pushUndoer(new undoers::DirtyArea(m_undo->getObjects(), image, dirty));
   }
 
   // Copy the flipped image into the image specified as argument.
@@ -1106,7 +1116,7 @@ void UndoTransaction::copyToCurrentMask(Mask* mask)
   ASSERT(mask);
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetMask(m_undoHistory->getObjects(),
+    m_undo->pushUndoer(new undoers::SetMask(m_undo->getObjects(),
         m_document));
 
   m_document->getMask()->copyFrom(mask);
@@ -1117,7 +1127,7 @@ void UndoTransaction::setMaskPosition(int x, int y)
   ASSERT(m_document->getMask());
 
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetMaskPosition(m_undoHistory->getObjects(), m_document));
+    m_undo->pushUndoer(new undoers::SetMaskPosition(m_undo->getObjects(), m_document));
 
   m_document->getMask()->setOrigin(x, y);
   m_document->resetTransformation();
@@ -1126,7 +1136,7 @@ void UndoTransaction::setMaskPosition(int x, int y)
 void UndoTransaction::deselectMask()
 {
   if (isEnabled())
-    m_undoHistory->pushUndoer(new undoers::SetMask(m_undoHistory->getObjects(),
+    m_undo->pushUndoer(new undoers::SetMask(m_undo->getObjects(),
         m_document));
 
   m_document->setMaskVisible(false);
diff --git a/src/undo_transaction.h b/src/undo_transaction.h
index 52176c26d..a1314f98c 100644
--- a/src/undo_transaction.h
+++ b/src/undo_transaction.h
@@ -27,6 +27,7 @@
 
 class Cel;
 class Document;
+class DocumentUndo;
 class Image;
 class Layer;
 class LayerImage;
@@ -34,7 +35,8 @@ class Mask;
 class Sprite;
 
 namespace undo {
-  class UndoHistory;
+  class ObjectsContainer;
+  class Undoer;
 }
 
 // High-level class to group a set of operations to modify the
@@ -73,6 +75,9 @@ public:
   // created).
   void commit();
 
+  void pushUndoer(undo::Undoer* undoer);
+  undo::ObjectsContainer* getObjects() const;
+
   // for sprite
   void setNumberOfFrames(int frames);
   void setCurrentFrame(int frame);
@@ -135,10 +140,12 @@ private:
 
   Document* m_document;
   Sprite* m_sprite;
-  undo::UndoHistory* m_undoHistory;
+  DocumentUndo* m_undo;
   bool m_closed;
   bool m_committed;
   bool m_enabledFlag;
+  const char* m_label;
+  undo::Modification m_modification;
 };
 
 #endif
diff --git a/src/undoers/close_group.cpp b/src/undoers/close_group.cpp
index 0868c9948..e944d6f79 100644
--- a/src/undoers/close_group.cpp
+++ b/src/undoers/close_group.cpp
@@ -26,6 +26,12 @@
 using namespace undo;
 using namespace undoers;
 
+CloseGroup::CloseGroup(const char* label, undo::Modification modification)
+  : m_label(label)
+  , m_modification(modification)
+{
+}
+
 void CloseGroup::dispose()
 {
   delete this;
@@ -33,5 +39,5 @@ void CloseGroup::dispose()
 
 void CloseGroup::revert(ObjectsContainer* objects, UndoersCollector* redoers)
 {
-  redoers->pushUndoer(new OpenGroup());
+  redoers->pushUndoer(new OpenGroup(m_label, m_modification));
 }
diff --git a/src/undoers/close_group.h b/src/undoers/close_group.h
index 2ae07366c..3d8847763 100644
--- a/src/undoers/close_group.h
+++ b/src/undoers/close_group.h
@@ -27,11 +27,19 @@ namespace undoers {
 class CloseGroup : public undo::Undoer
 {
 public:
+  CloseGroup(const char* label, undo::Modification modification);
   void dispose() OVERRIDE;
   size_t getMemSize() const OVERRIDE { return sizeof(*this); }
+  undo::Modification getModification() const { return m_modification; }
   bool isOpenGroup() const OVERRIDE { return false; }
   bool isCloseGroup() const OVERRIDE { return true; }
   void revert(undo::ObjectsContainer* objects, undo::UndoersCollector* redoers) OVERRIDE;
+
+  const char* getLabel() { return m_label; }
+
+private:
+  const char* m_label;
+  undo::Modification m_modification;
 };
 
 } // namespace undoers
diff --git a/src/undoers/open_group.cpp b/src/undoers/open_group.cpp
index 2a46b129d..b5d1e27b6 100644
--- a/src/undoers/open_group.cpp
+++ b/src/undoers/open_group.cpp
@@ -26,6 +26,12 @@
 using namespace undo;
 using namespace undoers;
 
+OpenGroup::OpenGroup(const char* label, undo::Modification modification)
+  : m_label(label)
+  , m_modification(modification)
+{
+}
+
 void OpenGroup::dispose()
 {
   delete this;
@@ -33,5 +39,5 @@ void OpenGroup::dispose()
 
 void OpenGroup::revert(ObjectsContainer* objects, UndoersCollector* redoers)
 {
-  redoers->pushUndoer(new CloseGroup());
+  redoers->pushUndoer(new CloseGroup(m_label, m_modification));
 }
diff --git a/src/undoers/open_group.h b/src/undoers/open_group.h
index 222697a33..185ef33d2 100644
--- a/src/undoers/open_group.h
+++ b/src/undoers/open_group.h
@@ -27,11 +27,19 @@ namespace undoers {
 class OpenGroup : public undo::Undoer
 {
 public:
+  OpenGroup(const char* label, undo::Modification modification);
   void dispose() OVERRIDE;
   size_t getMemSize() const OVERRIDE { return sizeof(*this); }
+  undo::Modification getModification() const { return m_modification; }
   bool isOpenGroup() const OVERRIDE { return true; }
   bool isCloseGroup() const OVERRIDE { return false; }
   void revert(undo::ObjectsContainer* objects, undo::UndoersCollector* redoers) OVERRIDE;
+
+  const char* getLabel() { return m_label; }
+
+private:
+  const char* m_label;
+  undo::Modification m_modification;
 };
 
 } // namespace undoers
diff --git a/src/undoers/undoer_base.h b/src/undoers/undoer_base.h
index e15418da6..05cdd8eda 100644
--- a/src/undoers/undoer_base.h
+++ b/src/undoers/undoer_base.h
@@ -17,6 +17,7 @@ namespace undoers {
 class UndoerBase : public undo::Undoer
 {
 public:
+  undo::Modification getModification() const OVERRIDE { return undo::DoesntModifyDocument; }
   bool isOpenGroup() const OVERRIDE { return false; }
   bool isCloseGroup() const OVERRIDE { return false; }
 };
diff --git a/src/util/celmove.cpp b/src/util/celmove.cpp
index d3d959abd..d603b920f 100644
--- a/src/util/celmove.cpp
+++ b/src/util/celmove.cpp
@@ -31,11 +31,9 @@
 #include "raster/layer.h"
 #include "raster/sprite.h"
 #include "raster/stock.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "undoers/add_cel.h"
 #include "undoers/add_image.h"
-#include "undoers/close_group.h"
-#include "undoers/open_group.h"
 #include "undoers/remove_cel.h"
 #include "undoers/remove_image.h"
 #include "undoers/replace_image.h"
@@ -52,7 +50,7 @@ static Layer* dst_layer = NULL;
 static int src_frame = 0;
 static int dst_frame = 0;
 
-static void remove_cel(Sprite* sprite, undo::UndoHistory* undo, LayerImage *layer, Cel *cel);
+static void remove_cel(Sprite* sprite, UndoTransaction& undo, LayerImage *layer, Cel *cel);
 
 void set_frame_to_handle(Layer *_src_layer, int _src_frame,
                          Layer *_dst_layer, int _dst_frame)
@@ -66,7 +64,6 @@ void set_frame_to_handle(Layer *_src_layer, int _src_frame,
 void move_cel(DocumentWriter& document)
 {
   Sprite* sprite = document->getSprite();
-  undo::UndoHistory* undo = document->getUndoHistory();
   Cel *src_cel, *dst_cel;
 
   ASSERT(src_layer != NULL);
@@ -82,13 +79,10 @@ void move_cel(DocumentWriter& document)
   src_cel = static_cast<LayerImage*>(src_layer)->getCel(src_frame);
   dst_cel = static_cast<LayerImage*>(dst_layer)->getCel(dst_frame);
 
-  if (undo->isEnabled()) {
-    undo->setLabel("Move Cel");
-    undo->setModification(undo::ModifyDocument);
-    undo->pushUndoer(new undoers::OpenGroup());
-
-    undo->pushUndoer(new undoers::SetCurrentLayer(undo->getObjects(), sprite));
-    undo->pushUndoer(new undoers::SetCurrentFrame(undo->getObjects(), sprite));
+  UndoTransaction undo(document, "Move Cel", undo::ModifyDocument);
+  if (undo.isEnabled()) {
+    undo.pushUndoer(new undoers::SetCurrentLayer(undo.getObjects(), sprite));
+    undo.pushUndoer(new undoers::SetCurrentFrame(undo.getObjects(), sprite));
   }
 
   sprite->setCurrentLayer(dst_layer);
@@ -102,15 +96,15 @@ void move_cel(DocumentWriter& document)
   /* move the cel in the same layer */
   if (src_cel != NULL) {
     if (src_layer == dst_layer) {
-      if (undo->isEnabled())
-        undo->pushUndoer(new undoers::SetCelFrame(undo->getObjects(), src_cel));
+      if (undo.isEnabled())
+        undo.pushUndoer(new undoers::SetCelFrame(undo.getObjects(), src_cel));
 
       src_cel->setFrame(dst_frame);
     }
     /* move the cel in different layers */
     else {
-      if (undo->isEnabled())
-        undo->pushUndoer(new undoers::RemoveCel(undo->getObjects(), src_layer, src_cel));
+      if (undo.isEnabled())
+        undo.pushUndoer(new undoers::RemoveCel(undo.getObjects(), src_layer, src_cel));
       static_cast<LayerImage*>(src_layer)->removeCel(src_cel);
 
       src_cel->setFrame(dst_frame);
@@ -127,11 +121,11 @@ void move_cel(DocumentWriter& document)
                                       sprite->getWidth(),
                                       sprite->getHeight(), 0);
 
-        if (undo->isEnabled()) {
-          undo->pushUndoer(new undoers::ReplaceImage(undo->getObjects(),
+        if (undo.isEnabled()) {
+          undo.pushUndoer(new undoers::ReplaceImage(undo.getObjects(),
               sprite->getStock(), src_cel->getImage()));
-          undo->pushUndoer(new undoers::SetCelPosition(undo->getObjects(), src_cel));
-          undo->pushUndoer(new undoers::SetCelOpacity(undo->getObjects(), src_cel));
+          undo.pushUndoer(new undoers::SetCelPosition(undo.getObjects(), src_cel));
+          undo.pushUndoer(new undoers::SetCelOpacity(undo.getObjects(), src_cel));
         }
 
         image_clear(dst_image, app_get_color_to_clear_layer(dst_layer));
@@ -144,15 +138,14 @@ void move_cel(DocumentWriter& document)
         image_free(src_image);
       }
 
-      if (undo->isEnabled())
-        undo->pushUndoer(new undoers::AddCel(undo->getObjects(), dst_layer, src_cel));
+      if (undo.isEnabled())
+        undo.pushUndoer(new undoers::AddCel(undo.getObjects(), dst_layer, src_cel));
 
       static_cast<LayerImage*>(dst_layer)->addCel(src_cel);
     }
   }
 
-  if (undo->isEnabled())
-    undo->pushUndoer(new undoers::CloseGroup());
+  undo.commit();
 
   set_frame_to_handle(NULL, 0, NULL, 0);
 }
@@ -160,7 +153,7 @@ void move_cel(DocumentWriter& document)
 void copy_cel(DocumentWriter& document)
 {
   Sprite* sprite = document->getSprite();
-  undo::UndoHistory* undo = document->getUndoHistory();
+  UndoTransaction undo(document, "Move Cel", undo::ModifyDocument);
   Cel *src_cel, *dst_cel;
 
   ASSERT(src_layer != NULL);
@@ -171,13 +164,9 @@ void copy_cel(DocumentWriter& document)
   src_cel = static_cast<LayerImage*>(src_layer)->getCel(src_frame);
   dst_cel = static_cast<LayerImage*>(dst_layer)->getCel(dst_frame);
 
-  if (undo->isEnabled()) {
-    undo->setLabel("Move Cel");
-    undo->setModification(undo::ModifyDocument);
-    undo->pushUndoer(new undoers::OpenGroup());
-
-    undo->pushUndoer(new undoers::SetCurrentLayer(undo->getObjects(), sprite));
-    undo->pushUndoer(new undoers::SetCurrentFrame(undo->getObjects(), sprite));
+  if (undo.isEnabled()) {
+    undo.pushUndoer(new undoers::SetCurrentLayer(undo.getObjects(), sprite));
+    undo.pushUndoer(new undoers::SetCurrentFrame(undo.getObjects(), sprite));
   }
 
   sprite->setCurrentLayer(dst_layer);
@@ -224,8 +213,8 @@ void copy_cel(DocumentWriter& document)
 
     /* add the image in the stock */
     image_index = sprite->getStock()->addImage(dst_image);
-    if (undo->isEnabled())
-      undo->pushUndoer(new undoers::AddImage(undo->getObjects(),
+    if (undo.isEnabled())
+      undo.pushUndoer(new undoers::AddImage(undo.getObjects(),
           sprite->getStock(), image_index));
 
     /* create the new cel */
@@ -233,19 +222,18 @@ void copy_cel(DocumentWriter& document)
     dst_cel->setPosition(dst_cel_x, dst_cel_y);
     dst_cel->setOpacity(dst_cel_opacity);
 
-    if (undo->isEnabled())
-      undo->pushUndoer(new undoers::AddCel(undo->getObjects(), dst_layer, dst_cel));
+    if (undo.isEnabled())
+      undo.pushUndoer(new undoers::AddCel(undo.getObjects(), dst_layer, dst_cel));
 
     static_cast<LayerImage*>(dst_layer)->addCel(dst_cel);
   }
 
-  if (undo->isEnabled())
-    undo->pushUndoer(new undoers::CloseGroup());
+  undo.commit();
 
   set_frame_to_handle(NULL, 0, NULL, 0);
 }
 
-static void remove_cel(Sprite* sprite, undo::UndoHistory* undo, LayerImage *layer, Cel *cel)
+static void remove_cel(Sprite* sprite, UndoTransaction& undo, LayerImage *layer, Cel *cel)
 {
   Image *image;
   Cel *it;
@@ -264,25 +252,21 @@ static void remove_cel(Sprite* sprite, undo::UndoHistory* undo, LayerImage *laye
       }
     }
 
-    if (undo->isEnabled())
-      undo->pushUndoer(new undoers::OpenGroup());
-
     if (!used) {
       // If the image is only used by this cel, we can remove the
       // image from the stock.
       image = sprite->getStock()->getImage(cel->getImage());
 
-      if (undo->isEnabled())
-        undo->pushUndoer(new undoers::RemoveImage(undo->getObjects(),
+      if (undo.isEnabled())
+        undo.pushUndoer(new undoers::RemoveImage(undo.getObjects(),
             sprite->getStock(), cel->getImage()));
 
       sprite->getStock()->removeImage(image);
       image_free(image);
     }
 
-    if (undo->isEnabled()) {
-      undo->pushUndoer(new undoers::RemoveCel(undo->getObjects(), layer, cel));
-      undo->pushUndoer(new undoers::CloseGroup());
+    if (undo.isEnabled()) {
+      undo.pushUndoer(new undoers::RemoveCel(undo.getObjects(), layer, cel));
     }
 
     // Remove the cel
diff --git a/src/util/expand_cel_canvas.cpp b/src/util/expand_cel_canvas.cpp
index c1c732f87..b3493bb51 100644
--- a/src/util/expand_cel_canvas.cpp
+++ b/src/util/expand_cel_canvas.cpp
@@ -27,16 +27,14 @@
 #include "raster/layer.h"
 #include "raster/sprite.h"
 #include "raster/stock.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "undoers/add_cel.h"
 #include "undoers/add_image.h"
-#include "undoers/close_group.h"
 #include "undoers/dirty_area.h"
-#include "undoers/open_group.h"
 #include "undoers/replace_image.h"
 #include "undoers/set_cel_position.h"
 
-ExpandCelCanvas::ExpandCelCanvas(Document* document, Sprite* sprite, Layer* layer, TiledMode tiledMode)
+ExpandCelCanvas::ExpandCelCanvas(Document* document, Sprite* sprite, Layer* layer, TiledMode tiledMode, UndoTransaction& undo)
   : m_document(document)
   , m_sprite(sprite)
   , m_layer(layer)
@@ -45,6 +43,7 @@ ExpandCelCanvas::ExpandCelCanvas(Document* document, Sprite* sprite, Layer* laye
   , m_celCreated(false)
   , m_closed(false)
   , m_committed(false)
+  , m_undo(undo)
 {
   if (m_layer->is_image()) {
     m_cel = static_cast<LayerImage*>(layer)->getCel(m_sprite->getCurrentFrame());
@@ -116,8 +115,6 @@ void ExpandCelCanvas::commit()
   ASSERT(!m_closed);
   ASSERT(!m_committed);
 
-  undo::UndoHistory* undo = m_document->getUndoHistory();
-
   // If the size of each image is the same, we can create an undo
   // with only the differences between both images.
   if (m_cel->getX() == m_originalCelX &&
@@ -135,18 +132,16 @@ void ExpandCelCanvas::commit()
       m_cel->setImage(m_sprite->getStock()->addImage(m_celImage));
 
       // Is the undo enabled?.
-      if (undo->isEnabled()) {
+      if (m_undo.isEnabled()) {
         // We can temporary remove the cel.
         static_cast<LayerImage*>(m_sprite->getCurrentLayer())->removeCel(m_cel);
 
         // We create the undo information (for the new m_celImage
         // in the stock and the new cel in the layer)...
-        undo->pushUndoer(new undoers::OpenGroup());
-        undo->pushUndoer(new undoers::AddImage(undo->getObjects(),
-                                               m_sprite->getStock(), m_cel->getImage()));
-        undo->pushUndoer(new undoers::AddCel(undo->getObjects(),
-                                             m_sprite->getCurrentLayer(), m_cel));
-        undo->pushUndoer(new undoers::CloseGroup());
+        m_undo.pushUndoer(new undoers::AddImage(m_undo.getObjects(),
+                                                m_sprite->getStock(), m_cel->getImage()));
+        m_undo.pushUndoer(new undoers::AddCel(m_undo.getObjects(),
+                                              m_sprite->getCurrentLayer(), m_cel));
 
         // And finally we add the cel again in the layer.
         static_cast<LayerImage*>(m_sprite->getCurrentLayer())->addCel(m_cel);
@@ -155,12 +150,12 @@ void ExpandCelCanvas::commit()
     // If the m_celImage was already created before the whole process...
     else {
       // Add to the undo history the differences between m_celImage and m_dstImage
-      if (undo->isEnabled()) {
+      if (m_undo.isEnabled()) {
         UniquePtr<Dirty> dirty(new Dirty(m_celImage, m_dstImage));
 
         dirty->saveImagePixels(m_celImage);
         if (dirty != NULL)
-          undo->pushUndoer(new undoers::DirtyArea(undo->getObjects(), m_celImage, dirty));
+          m_undo.pushUndoer(new undoers::DirtyArea(m_undo.getObjects(), m_celImage, dirty));
       }
 
       // Copy the destination to the cel image.
@@ -170,23 +165,20 @@ void ExpandCelCanvas::commit()
   // If the size of both images are different, we have to
   // replace the entire image.
   else {
-    if (undo->isEnabled()) {
-      undo->pushUndoer(new undoers::OpenGroup());
-
+    if (m_undo.isEnabled()) {
       if (m_cel->getX() != m_originalCelX ||
           m_cel->getY() != m_originalCelY) {
         int x = m_cel->getX();
         int y = m_cel->getY();
         m_cel->setPosition(m_originalCelX, m_originalCelY);
 
-        undo->pushUndoer(new undoers::SetCelPosition(undo->getObjects(), m_cel));
+        m_undo.pushUndoer(new undoers::SetCelPosition(m_undo.getObjects(), m_cel));
 
         m_cel->setPosition(x, y);
       }
 
-      undo->pushUndoer(new undoers::ReplaceImage(undo->getObjects(),
-                                                 m_sprite->getStock(), m_cel->getImage()));
-      undo->pushUndoer(new undoers::CloseGroup());
+      m_undo.pushUndoer(new undoers::ReplaceImage(m_undo.getObjects(),
+                                                  m_sprite->getStock(), m_cel->getImage()));
     }
 
     // Replace the image in the stock.
diff --git a/src/util/expand_cel_canvas.h b/src/util/expand_cel_canvas.h
index 6c5757fba..513de4ce8 100644
--- a/src/util/expand_cel_canvas.h
+++ b/src/util/expand_cel_canvas.h
@@ -26,6 +26,7 @@ class Document;
 class Image;
 class Layer;
 class Sprite;
+class UndoTransaction;
 
 // This class can be used to expand the canvas of the current cel to
 // the visible portion of sprite. If the user cancels the operation,
@@ -36,7 +37,7 @@ class Sprite;
 class ExpandCelCanvas
 {
 public:
-  ExpandCelCanvas(Document* document, Sprite* sprite, Layer* layer, TiledMode tiledMode);
+  ExpandCelCanvas(Document* document, Sprite* sprite, Layer* layer, TiledMode tiledMode, UndoTransaction& undo);
   ~ExpandCelCanvas();
 
   // Commit changes made in getDestCanvas() in the cel's image. Adds
@@ -75,6 +76,7 @@ private:
   Image* m_dstImage;
   bool m_closed;
   bool m_committed;
+  UndoTransaction& m_undo;
 };
 
 #endif
diff --git a/src/widgets/editor/pixels_movement.cpp b/src/widgets/editor/pixels_movement.cpp
index d22e326be..5a15e1c6a 100644
--- a/src/widgets/editor/pixels_movement.cpp
+++ b/src/widgets/editor/pixels_movement.cpp
@@ -448,7 +448,8 @@ void PixelsMovement::stampImage()
       // Expand the canvas to paste the image in the fully visible
       // portion of sprite.
       ExpandCelCanvas expandCelCanvas(documentWriter, m_sprite,
-                                      m_sprite->getCurrentLayer(), TILED_NONE);
+                                      m_sprite->getCurrentLayer(), TILED_NONE,
+                                      m_undoTransaction);
 
       image_merge(expandCelCanvas.getDestCanvas(), image,
                   -expandCelCanvas.getCel()->getX(),
diff --git a/src/widgets/editor/tool_loop_impl.cpp b/src/widgets/editor/tool_loop_impl.cpp
index d0fb0f818..efb3bd67e 100644
--- a/src/widgets/editor/tool_loop_impl.cpp
+++ b/src/widgets/editor/tool_loop_impl.cpp
@@ -35,7 +35,7 @@
 #include "tools/tool.h"
 #include "tools/tool_loop.h"
 #include "ui/gui.h"
-#include "undo/undo_history.h"
+#include "undo_transaction.h"
 #include "util/expand_cel_canvas.h"
 #include "widgets/color_bar.h"
 #include "widgets/editor/editor.h"
@@ -71,6 +71,7 @@ class ToolLoopImpl : public tools::ToolLoop
   tools::ToolLoop::Button m_button;
   int m_primary_color;
   int m_secondary_color;
+  UndoTransaction m_undoTransaction;
   ExpandCelCanvas m_expandCelCanvas;
 
 public:
@@ -94,7 +95,13 @@ public:
     , m_button(button)
     , m_primary_color(color_utils::color_for_layer(primary_color, layer))
     , m_secondary_color(color_utils::color_for_layer(secondary_color, layer))
-    , m_expandCelCanvas(document, sprite, layer, m_tiled_mode)
+    , m_undoTransaction(m_document,
+                        m_tool->getText().c_str(),
+                        ((getInk()->isSelection() ||
+                          getInk()->isEyedropper() ||
+                          getInk()->isScrollMovement()) ? undo::DoesntModifyDocument:
+                                                          undo::ModifyDocument))
+    , m_expandCelCanvas(document, sprite, layer, m_tiled_mode, m_undoTransaction)
   {
     // Settings
     ISettings* settings = m_context->getSettings();
@@ -146,19 +153,6 @@ public:
 
     m_offset.x = -x1;
     m_offset.y = -y1;
-
-    // Set undo label for any kind of undo used in the whole loop
-    if (m_document->getUndoHistory()->isEnabled()) {
-      m_document->getUndoHistory()->setLabel(m_tool->getText().c_str());
-
-      if (getInk()->isSelection() ||
-          getInk()->isEyedropper() ||
-          getInk()->isScrollMovement()) {
-        m_document->getUndoHistory()->setModification(undo::DoesntModifyDocument);
-      }
-      else
-        m_document->getUndoHistory()->setModification(undo::ModifyDocument);
-    }
   }
 
   ~ToolLoopImpl()
@@ -172,6 +166,8 @@ public:
       else if (getInk()->isSelection()) {
         m_document->generateMaskBoundaries();
       }
+
+      m_undoTransaction.commit();
     }
 
     // If the trace was not canceled or it is not a 'paint' ink...