1 files changed, 1 insertions, 1 deletions
diff --git a/FL/glu.h b/FL/glu.h
index 4ab7b1ea2..cce6243fa 100644
--- a/FL/glu.h
+++ b/FL/glu.h
@@ -27,7 +27,7 @@
 #  define FL_glu_H
 
 #  include "Enumerations.H" // for color names
-#  ifdef WIN32
+#  ifdef _WIN32
 #    include <windows.h>
 #  endif
 #  ifndef APIENTRY