diff --git a/backends/graphics/opengl/opengl-sys.h b/backends/graphics/opengl/opengl-sys.h
index 97ebb887772..5e754bb328a 100644
--- a/backends/graphics/opengl/opengl-sys.h
+++ b/backends/graphics/opengl/opengl-sys.h
@@ -30,10 +30,6 @@
 #include "backends/platform/sdl/sdl-sys.h"
 #endif
 
-#ifdef __MORPHOS__
-#define USE_GLES_MODE 1
-#endif
-
 // On OS X we only support GL contexts. The reason is that Apple's GL interface
 // uses "void *" for GLhandleARB which is not type compatible with GLint. This
 // kills our aliasing trick for extension functions and thus would force us to