diff --git a/src/GNUstep.h b/src/GNUstep.h
index d6b050b9..52d1e8df 100644
--- a/src/GNUstep.h
+++ b/src/GNUstep.h
@@ -69,7 +69,9 @@ enum {
   WMTitledWindowMask = 1,
   WMClosableWindowMask = 2,
   WMMiniaturizableWindowMask = 4,
-  WMResizableWindowMask = 8
+  WMResizableWindowMask = 8,
+  WMIconWindowMask = 64,
+  WMMiniWindowMask = 128
 };
 #endif /* _WINGS_H_ */