diff --git a/src/osgDB/FileNameUtils.cpp b/src/osgDB/FileNameUtils.cpp
index 879cf2c2c..12516b576 100644
--- a/src/osgDB/FileNameUtils.cpp
+++ b/src/osgDB/FileNameUtils.cpp
@@ -18,6 +18,7 @@
 #include <osgDB/FileUtils>
 
 #ifdef WIN32
+    #define _WIN32_WINNT 0x0500
     #include <windows.h>
 #endif