The behaviour is correct. Class.forName() is a bad classloading api that shouldn't be used except in the most trivial of environments. You need to figure out why your generated class is not visible from the context classloader (the classloader of the MDB). Most likely because you've created your own classloader that is invisible from the rest of the classloading system or something like this? http://jira.jboss.org/jira/browse/JBAS-3691 i.e. you used a backdoor to defineClass() on a classloader that never invokes findLoadedClass() (like IBM started doing with their proxy generation). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4061942#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...