add space
diff --git a/Lib/test/test_lib2to3.py b/Lib/test/test_lib2to3.py
index e332062..10dcec6 100644
--- a/Lib/test/test_lib2to3.py
+++ b/Lib/test/test_lib2to3.py
@@ -7,7 +7,7 @@
 def suite():
     tests = unittest.TestSuite()
     loader = unittest.TestLoader()
-    for m in (test_fixers,test_pytree,test_util, test_refactor):
+    for m in (test_fixers, test_pytree,test_util, test_refactor):
         tests.addTests(loader.loadTestsFromModule(m))
     return tests