--- SDL-1.2.15.old/include/SDL_opengl.h
+++ SDL-1.2.15/include/SDL_opengl.h
@@ -24,6 +24,10 @@
  *  This is a simple file to encapsulate the OpenGL API headers
  */
 
+#ifndef NO_SDL_GLEXT
+#define NO_SDL_GLEXT 1
+#endif
+
 #include "SDL_config.h"
 
 #ifdef __WIN32__