[Zope] File with History

hi I'm trying to add 'History' for a File object. What i have done is this : class File(Persistent, Implicit, PropertyManager, RoleManager, Item_w__name__, Cacheable, History.Historical): ------------------------- !!!! for File class in Image.py from lib/python/OFS After restraing Zope, the History tab was present and working. Is there a way to do the same thing without modifying the Image.py file ?? Something like a 'HotFix' product ?? 10x rares