Ok, so you've got hibernate somewhere in the classpath of your app (at runtime) right? Remove it, and you'll drop down to the generic (JPA) PeristenceProvider, which isn't as good (it can only deal with entities which are mapped using JPA annotations) but works just fine otherwise. If you want to write a ToplinkPersistenceProvider (it would be cool to have something like this in the wiki), all you need to do is copy the annotations on HibernatePersistenceProvider (replacing the classDependency with one for the toplink equivalent), and just override those methods from PersistenceProvider which can be better implemented with the underlying EntityManager from Toplink than just the JPA one. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4059946#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...