Did you set useRegionBasedMarshalling to true? Set that to true, and then get the region for which your nodes are in and register your class loader onto the region. That will ensure your class loader being used. Weird that you still see the bug though, the MarshalledValueInputStream delegates to an ObjectInputStream. :/ Do you have a repeatable unit test that recreates this, perhaps it is something I can add to our testsuite and make sure we have a proper solution for it. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4172231#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...