Sorry, not the expert answer here but I do not see any references to orh.hibernate.Session anywhere in org.jbpm.pvm.internal.session.DbSession. That's the interface that org.jbpm.pvm.internal.hibernate.DbSessionImpl implements, and that has loads of Hibernate imports and references, but hey, it is a.) an implementation class and b.) it says so in the package name itself, that it is a hibernate implementation of DbSessionImpl. Dunno how much that helped, View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4238656#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...