diff --git a/src/allmydata/test/test_stringutils.py b/src/allmydata/test/test_stringutils.py
index e2dba0c5b..73a67e6b9 100644
--- a/src/allmydata/test/test_stringutils.py
+++ b/src/allmydata/test/test_stringutils.py
@@ -131,7 +131,7 @@ class StringUtilsNonUnicodePlatform(unittest.TestCase):
                               open_unicode,
                               u'lumière')
 
-class StringUtils():
+class StringUtils:
     def setUp(self):
         # Mock sys.platform because unicode_platform() uses it
         self.original_platform = sys.platform