diff --git a/simgear/screen/extensions.hxx b/simgear/screen/extensions.hxx
index f97e0ad7..30f63e21 100644
--- a/simgear/screen/extensions.hxx
+++ b/simgear/screen/extensions.hxx
@@ -24,7 +24,7 @@
 #ifndef __SG_EXTENSIONS_HXX
 #define __SG_EXTENSIONS_HXX 1
 
-#if defined(__CYGWIN__)  /* && !defined(USING_X) */
+#if defined(__CYGWIN__) && !defined(WIN32) /* && !defined(USING_X) */
 #define WIN32
 #endif