diff --git a/setup.py b/setup.py
index e580180..b9d73db 100644
--- a/setup.py
+++ b/setup.py
@@ -58,7 +58,7 @@ def test_discover():
         'dheater',
     ],
 
-    scripts = ['tools/dh_param_priv_key_size_setter.py'],
+    scripts = ['tools/dh_param_priv_key_size_setter'],
 
     test_suite='setup.test_discover',