--- a/devtools/testlib.py	Wed Sep 09 08:32:49 2015 +0200
+++ b/devtools/testlib.py	Thu Oct 08 18:09:10 2015 +0200
@@ -728,7 +728,7 @@
 
     def assertModificationDateGreater(self, entity, olddate):
         entity.cw_attr_cache.pop('modification_date', None)
-        self.assertTrue(entity.modification_date > olddate)
+        self.assertGreater(entity.modification_date, olddate)
 
     def assertMessageEqual(self, req, params, expected_msg):
         msg = req.session.data[params['_cwmsgid']]