diff --git a/rfb/keysym.h b/rfb/keysym.h
index 282d818..219f95b 100644
--- a/rfb/keysym.h
+++ b/rfb/keysym.h
@@ -1,5 +1,4 @@
-#ifndef KEYSYM_H
-#define KEYSYM_H
+#ifndef XK_0
 
 /* $XConsortium: keysym.h,v 1.15 94/04/17 20:10:55 rws Exp $ */