diff --git a/product/ERP5Type/tests/testMemcachedTool.py b/product/ERP5Type/tests/testMemcachedTool.py
index 624ebce9fbd77087775c447b7a9aaa7a2ab06777..2e066016d009e6016a74cf62efe36fb2cc82e1a2 100644
--- a/product/ERP5Type/tests/testMemcachedTool.py
+++ b/product/ERP5Type/tests/testMemcachedTool.py
@@ -201,8 +201,8 @@ class TestMemcachedTool(ERP5TypeTestCase):
     transaction.commit()
     self.assertEquals(tested_dict.get(key), value)
     transaction.commit()
-    # Sleep 10s
-    time.sleep(self.expiration_time)
+    # Sleep epliration_time + 1 second to be sure that it is well expired
+    time.sleep(self.expiration_time + 1)
     # now value should have expired
     self.assertRaises(KeyError, tested_dict.__getitem__, key)