diff --git a/reactos/lib/mesa32/src/drivers/windows/gdi/wmesadef.h b/reactos/lib/mesa32/src/drivers/windows/gdi/wmesadef.h
index 3c267aa0f6a..fc0cbe045e3 100644
--- a/reactos/lib/mesa32/src/drivers/windows/gdi/wmesadef.h
+++ b/reactos/lib/mesa32/src/drivers/windows/gdi/wmesadef.h
@@ -70,7 +70,7 @@
 
 
 #include <windows.h>
-#include <GL\gl.h>
+#include "GL/gl.h"
 #include "context.h"
 #ifdef DDRAW
 #define DIRECTDRAW_VERSION 0x0100