--- a/RenderSystems/Direct3D11/include/OgreD3D11Device.h
+++ b/RenderSystems/Direct3D11/include/OgreD3D11Device.h
@@ -30,6 +30,10 @@
 
 
 #include "OgreD3D11Prerequisites.h"
+#if (_WIN32_WINNT < 0x603)
+#define _WIN32_WINNT 0x603
+#endif
+#include <windows.h>
 
 namespace Ogre
 {
