diff --git a/src/osgDB/FileNameUtils.cpp b/src/osgDB/FileNameUtils.cpp
index 383638e93..34b740a86 100644
--- a/src/osgDB/FileNameUtils.cpp
+++ b/src/osgDB/FileNameUtils.cpp
@@ -19,9 +19,6 @@
 #include <osgDB/FileUtils>
 
 #ifdef WIN32
-#if !defined(__MINGW32__)
-    #define _WIN32_WINNT 0x0500
-#endif
     #include <windows.h>
 #endif