diff --git a/cinder/objects/base.py b/cinder/objects/base.py
index fd202cb71..be7eb426f 100644
--- a/cinder/objects/base.py
+++ b/cinder/objects/base.py
@@ -223,6 +223,8 @@ class CinderPersistentObject(object):
 
     This adds the fields that we use in common for all persistent objects.
     """
+    OPTIONAL_FIELDS = []
+
     Not = db.Not
     Case = db.Case