diff -r 3cc6154b94a3 -r 9ca33768473c devtools/testlib.py
--- a/devtools/testlib.py	Mon Sep 14 11:15:47 2015 +0200
+++ b/devtools/testlib.py	Mon Oct 12 10:53:35 2015 +0200
@@ -528,16 +528,18 @@
                 origperms = erschema.permissions[action]
                 erschema.set_action_permissions(action, actionperms)
                 torestore.append([erschema, action, origperms])
-        yield
-        for erschema, action, permissions in torestore:
-            if action is None:
-                erschema.permissions = permissions
-            else:
-                erschema.set_action_permissions(action, permissions)
+        try:
+            yield
+        finally:
+            for erschema, action, permissions in torestore:
+                if action is None:
+                    erschema.permissions = permissions
+                else:
+                    erschema.set_action_permissions(action, permissions)
 
     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']]