diff --git a/include/GL/glu.h b/include/GL/glu.h
index 4de6965c702..54eb836d53c 100644
--- a/include/GL/glu.h
+++ b/include/GL/glu.h
@@ -30,6 +30,10 @@
 #ifndef __glu_h__
 #define __glu_h__
 
+#if defined(USE_MGL_NAMESPACE)
+#include "glu_mangle.h"
+#endif
+
 #include <GL/gl.h>
 
 #ifdef __cplusplus