Index: src/tld/tests/test_commands.py
--- src/tld/tests/test_commands.py.orig
+++ src/tld/tests/test_commands.py
@@ -34,7 +34,7 @@ class TestCommands(unittest.TestCase):
     def test_2_update_tld_names_module(self):
         """Test updating the tld names (re-fetch mozilla source)."""
         res = subprocess.check_output(
-            shlex.split('python src/tld/commands/update_tld_names.py')
+            shlex.split("${MODPY_BIN} src/tld/commands/update_tld_names.py")
         ).strip()
         self.assertEqual(res, b'True')
         return res
