diff --git a/Externals/libpng/CMakeLists.txt b/Externals/libpng/CMakeLists.txt
index 122007c7c5..8489e6944a 100644
--- a/Externals/libpng/CMakeLists.txt
+++ b/Externals/libpng/CMakeLists.txt
@@ -18,5 +18,7 @@ set(SRCS
   pngwtran.c
   pngwutil.c
 )
-add_definitions(-Wno-self-assign)
+if(NOT MSVC)
+	add_definitions(-Wno-self-assign)
+endif()
 add_library(png STATIC ${SRCS})