diff --git a/panda/src/windisplay/winGraphicsWindow.h b/panda/src/windisplay/winGraphicsWindow.h
index 82da55edcd..0bd7736ad9 100644
--- a/panda/src/windisplay/winGraphicsWindow.h
+++ b/panda/src/windisplay/winGraphicsWindow.h
@@ -17,13 +17,17 @@
 
 #include "pandabase.h"
 #include "graphicsWindow.h"
-#define WIN32_LEAN_AND_MEAN 1
+#ifndef WIN32_LEAN_AND_MEAN
+	#define WIN32_LEAN_AND_MEAN 1
+#endif
 #include <windows.h>
 
 class WinGraphicsPipe;
 
-#define PM_ACTIVE   (WM_APP+123)
-#define PM_INACTIVE  (WM_APP+124)
+#define PM_ACTIVE   (WM_APP+123)
+
+#define PM_INACTIVE  (WM_APP+124)
+
 
 
 ////////////////////////////////////////////////////////////////////