diff --git a/setup.py b/setup.py
index 2939eeee2..8dad50195 100644
--- a/setup.py
+++ b/setup.py
@@ -297,8 +297,6 @@ def get_version_tofu(path=_HERE):
     ),
 ]
 
-extensions = cythonize(extensions, annotate=True)
-
 
 setup(
     name="tofu",
@@ -416,6 +414,7 @@ def get_version_tofu(path=_HERE):
     #    ],
     # },
     ext_modules=extensions,
-    cmdclass={"build_ext": build_ext, "clean": CleanCommand},
+    cmdclass={"build_ext": cth.Build.build_ext,
+              "clean": CleanCommand},
     include_dirs=[np.get_include()],
 )