diff --git a/tests/test-lock.py b/tests/test-lock.py
--- a/tests/test-lock.py
+++ b/tests/test-lock.py
@@ -2,11 +2,12 @@ from __future__ import absolute_import
 
 import copy
 import errno
-import silenttestrunner
 import tempfile
 import types
 import unittest
 
+import silenttestrunner
+
 from mercurial import (
     encoding,
     error,