--- config/gen/opengl.pm.orig	2016-02-15 01:33:18.000000000 -0700
+++ config/gen/opengl.pm	2019-09-11 22:33:00.000000000 -0700
@@ -443,8 +443,8 @@
         '/usr/local/include/GL/*.h',
 
         # Mac OS X
-        '/System/Library/Frameworks/OpenGL.framework/Headers/*.h',
-        '/System/Library/Frameworks/GLUT.framework/Headers/*.h',
+        '__MACPORTS_SDK_ROOT_/System/Library/Frameworks/OpenGL.framework/Headers/*.h',
+        '__MACPORTS_SDK_ROOT_/System/Library/Frameworks/GLUT.framework/Headers/*.h',
 
         # Cygwin
         '/usr/include/w32api/GL/*.h',