diff --git a/product/ERP5Type/tests/ERP5TypeTestCase.py b/product/ERP5Type/tests/ERP5TypeTestCase.py
index faa4913a00e751c479f80468fb759cbf94ca616b..8b53621bbcce90da39dc014efb10c72e353a8dae 100644
--- a/product/ERP5Type/tests/ERP5TypeTestCase.py
+++ b/product/ERP5Type/tests/ERP5TypeTestCase.py
@@ -1312,8 +1312,7 @@ def fortify():
   CacheEntry__init__ = CacheEntry.__init__
   def __init__(self, value, *args, **kw):
     # this will raise TypeError if you try to cache a persistent object
-    if value is not None:
-      dumps(value)
+    dumps(value)
     CacheEntry__init__(self, value, *args, **kw)
   CacheEntry.__init__ = __init__
   # randomize priorities of activities in a deterministic way