Hi there! At the moment I'm trying to wrap my mind around pb objects. I learned from the pb.Copyable howto (http://twistedmatrix.com/documents/current/howto/pb-copyable) that I must setUnjellyableForClass every object that could be sent from a client. I need a simple empty utility class like this: class Info(pb.Copyable): def __init__(self, obj=None): if obj: self.__dict__.update(obj.__dict__) Because I can use such in server as well as in client, I defined the class in the server and imported it in the client. Nevertheless I get an InsecureJelly exception in the server. If I setUnjellyable... it in the server as in pb.setUnjellyableForClass(Info, Info) I get an AttributeError: Info instance has no attribute 'unjellyFor' Is there any way to declare this class only once and not separate for server and client? Best regards, Henning Hraban Ramm Südkurier Medienhaus / MediaPro Support/Admin/Development Dept.