diff --git a/glincludes.h b/glincludes.h
index ebfd85065aec3bdfa8e7e7c38c3e9e060660b6ae..52e1aa3fb586b2fdd3b2b2cff31e271c4c33a69b 100644
--- a/glincludes.h
+++ b/glincludes.h
@@ -3,7 +3,12 @@
 
 // TODO: test on mac
 
-#define GL_GLEXT_PROTOTYPES 1
+// OpenGL>=2.1 not found, try GLEW
+#include <GL/glew.h>
+#if (!defined GLEW_VERSION_2_1) || (!defined GL_VERSION_2_1)
+  #error OpenGL 2.1 or GLEW is required
+#endif
+
 #ifdef __APPLE__
   #include<OpenGL/gl.h>
   #include<OpenGL/glu.h>
@@ -17,15 +22,4 @@
   //#include <GL/glext.h>
 #endif
 
-// GLew might not be needed on mac, or if a recent version of OpenGL is present
-//#ifndef __APPLE__
-  #ifndef GL_VERSION_2_1
-    // OpenGL>=2.1 not found, try GLEW
-    #include <GL/glew.h>
-    #ifndef GLEW_VERSION_2_1
-      #error OpenGL 2.1 or GLEW is required
-    #endif
-  #endif
-//#endif
-
 #endif // GLINCLUDES_H
diff --git a/pano_interface_1.pro b/pano_interface_1.pro
index 360e31a8c5d4ebd11113e69265b2b20bf71d2c40..73d79992cea9eb2d86b0a0a9934a17e08166c557 100644
--- a/pano_interface_1.pro
+++ b/pano_interface_1.pro
@@ -56,7 +56,7 @@ LIBS += -L$${PFROOT}/freeglut/lib
 LIBS += -L$${PFROOT}/GnuWin32/lib
 LIBS += -L$${PFROOT}/GnuWin32/bin
 LIBS += -L$${PFROOT}/glew-1.9.0/lib
-LIBS += -lglew32s -lfreeglut -lglu32 -lopengl32 -ljpeg -lpng #-llibnetpbm10
+LIBS += -lglew32s -lfreeglut -lglu32 -lopengl32 -ljpeg -llibpng -llibnetpbm10
 }
 
 TARGET = pano_interface_1