diff --git a/auto/src/glew_head.h b/auto/src/glew_head.h
index ac72d63..c9f1189 100644
--- a/auto/src/glew_head.h
+++ b/auto/src/glew_head.h
@@ -5,6 +5,9 @@
 #if defined(__gl_h_) || defined(__GL_H__) || defined(__X_GL_H)
 #error gl.h included before glew.h
 #endif
+#if defined(__gl2_h_)
+#error gl2.h included before glew.h
+#endif
 #if defined(__REGAL_H__)
 #error Regal.h included before glew.h
 #endif
@@ -16,6 +19,7 @@
 #endif
 
 #define __gl_h_
+#define __gl2_h_
 #define __GL_H__
 #define __REGAL_H__
 #define __X_GL_H