diff -Nur ClanLib-0.6.5/Sources/GL/GLX/displaycard_glx.cpp ClanLib-0.6.5-GL/Sources/GL/GLX/displaycard_glx.cpp
--- ClanLib-0.6.5/Sources/GL/GLX/displaycard_glx.cpp	2002-02-16 17:10:41.000000000 +0100
+++ ClanLib-0.6.5-GL/Sources/GL/GLX/displaycard_glx.cpp	2003-05-30 20:07:40.000000000 +0200
@@ -11,6 +11,7 @@
 
 	------------------------------------------------------------------------
 */
+#define GLX_GLXEXT_PROTOTYPES 
 
 #ifdef USE_OPENGL