diff --git a/setup.py b/setup.py
index 0ac3cbb..12f3337 100644
--- a/setup.py
+++ b/setup.py
@@ -89,7 +89,7 @@ def _extension(modpath):
         overflowcheck=True,
         language_level=3,
     )
-) if cythonize is not None else ()
+) if cythonize is not None and PY3 else []
 
 
 class BuildFailed(Exception):