diff --git a/setup.py b/setup.py
index bfad34a..cfb30c3 100644
--- a/setup.py
+++ b/setup.py
@@ -68,9 +68,6 @@ setup(name='jsonnet',
       author='David Cunningham',
       author_email='dcunnin@google.com',
       version=get_version(),
-      cmdclass={
-          'build_ext': BuildJsonnetExt,
-      },
       ext_modules=[jsonnet_ext],
       test_suite="python._jsonnet_test",
 )