diff --git a/gltbx/gl.py b/gltbx/gl.py
index e21cdd52f7..fae1e6b942 100644
--- a/gltbx/gl.py
+++ b/gltbx/gl.py
@@ -1,10 +1,11 @@
 from __future__ import absolute_import, division, print_function
-# import boost_adaptbx.boost.python as bp
-# ext = bp.import_ext("gltbx_gl_ext")
-# from gltbx_gl_ext import *
-import OpenGL  # implicit import
-from OpenGL.GLU import *
-from OpenGL.GL import *
+try:
+  import OpenGL  # implicit import
+  from OpenGL.GL import *
+except ImportError:
+  import boost_adaptbx.boost.python as bp
+  ext = bp.import_ext("gltbx_gl_ext")
+  from gltbx_gl_ext import *
 
 def __function_taking_transposed_matrix(f):
   def wrapper(m):
diff --git a/gltbx/glu.py b/gltbx/glu.py
index 4676b1746d..85e21ab951 100644
--- a/gltbx/glu.py
+++ b/gltbx/glu.py
@@ -1,6 +1,8 @@
 from __future__ import absolute_import, division, print_function
-# import boost_adaptbx.boost.python as bp
-# ext = bp.import_ext("gltbx_glu_ext")
-# from gltbx_glu_ext import *
-import OpenGL  # implicit import
-from OpenGL.GLU import *
+try:
+  import OpenGL  # implicit import
+  from OpenGL.GLU import *
+except ImportError:
+  import boost_adaptbx.boost.python as bp
+  ext = bp.import_ext("gltbx_glu_ext")
+  from gltbx_glu_ext import *