diff --git a/simgear/screen/extensions.hxx b/simgear/screen/extensions.hxx
index a0c09fd4..c58f4416 100644
--- a/simgear/screen/extensions.hxx
+++ b/simgear/screen/extensions.hxx
@@ -36,9 +36,7 @@
 
 #include <osg/GL>
 
-#if defined (WIN32)
-#  include <GL/wgl.h>
-#elif !defined(__APPLE__)
+#if !defined(__APPLE__) && !defined(WIN32)
 #  include <GL/glx.h>
 #endif