diff --git a/auto/src/glew_head.h b/auto/src/glew_head.h
index e3f6eb2..c5592e1 100644
--- a/auto/src/glew_head.h
+++ b/auto/src/glew_head.h
@@ -2,7 +2,7 @@
 #define __glew_h__
 #define __GLEW_H__
 
-#if defined(__gl_h_) || defined(__GL_H__) || defined(__X_GL_H)
+#if defined(__gl_h_) || defined(__GL_H__) || defined(_GL_H) || defined(__X_GL_H)
 #error gl.h included before glew.h
 #endif
 #if defined(__gl2_h_)
@@ -24,6 +24,7 @@
 #define __gl_h_
 #define __gl2_h_
 #define __GL_H__
+#define _GL_H
 #define __gltypes_h_
 #define __REGAL_H__
 #define __X_GL_H