diff --git a/src/base/CMakeLists.txt b/src/base/CMakeLists.txt
index 85cd53281..dfe835d9d 100644
--- a/src/base/CMakeLists.txt
+++ b/src/base/CMakeLists.txt
@@ -90,6 +90,7 @@ add_library(base-lib ${BASE_SOURCES})
 target_link_libraries(base-lib modp_b64)
 
 if(WIN32)
+  add_definitions(-D_CRT_SECURE_NO_WARNINGS)
   target_link_libraries(base-lib dbghelp shlwapi)
 else()
   find_library(DL_LIBRARY NAMES dl)
diff --git a/src/config.h b/src/config.h
index 26d45e7db..0e35456ff 100644
--- a/src/config.h
+++ b/src/config.h
@@ -14,7 +14,9 @@
 // In MSVC
 #ifdef _MSC_VER
   // Avoid warnings about insecure standard C++ functions
+  #ifndef _CRT_SECURE_NO_WARNINGS
   #define _CRT_SECURE_NO_WARNINGS
+  #endif
 
   // Disable warning C4355 in MSVC: 'this' used in base member initializer list
   #pragma warning(disable:4355)
diff --git a/src/doc/CMakeLists.txt b/src/doc/CMakeLists.txt
index 7dc6a1afe..e43f6dafb 100644
--- a/src/doc/CMakeLists.txt
+++ b/src/doc/CMakeLists.txt
@@ -1,5 +1,9 @@
 # Aseprite Document Library
-# Copyright (C) 2001-2015 David Capello
+# Copyright (C) 2001-2016 David Capello
+
+if(WIN32)
+  add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+endif()
 
 add_library(doc-lib
   algo.cpp
diff --git a/src/ui/CMakeLists.txt b/src/ui/CMakeLists.txt
index 3da091608..b787daf80 100644
--- a/src/ui/CMakeLists.txt
+++ b/src/ui/CMakeLists.txt
@@ -1,5 +1,9 @@
 # ASEPRITE
-# Copyright (C) 2001-2015  David Capello
+# Copyright (C) 2001-2016  David Capello
+
+if(WIN32)
+  add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+endif()
 
 add_library(ui-lib
   accelerator.cpp