I had a few hours today to have a look at this so was examining your code to see how I would solve my problem. Please correct me if I'm wrong! I can't see how you could ever call annotateClass as class information is persisted on the stream seperately to the objects. You are using the ClassMetaData class to describe a class, and you persisting that information using the StreamingClass class. I'm guessing that to change jboss serialization such that different class loaders can be used for different serialized objects, I would have to include the relevant information within the ClassMetaData... and change StreamingClass such that it can store the classloader information in saveStream and read the class loader information at the beginning of the readStream method. Does this make sense? Ben View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4003991#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...