I'm working on an application server bug fix that I need some advice with, as Hibernate ORM 4.3.6.Final is throwing a "o.h.DuplicateMappingException: Duplicate query mapping EventManager.MyEvents" after I fixed a jar-file reference bug in WildFly (when I try to deploy a test case). Prior to my jar-file bug fix, the jar-file URL was incorrectly pointing at the wrong location (zero files were returned when file url was accessed). As a result, entities were loaded only once from the ear/lib jar. Now, with my bug fix (getJarFileUrls now returns a valid URL for jar-file) , WildFly is getting the DuplicateMappingException because the entity is loaded twice (even though *exclude-unlisted-classes* is in the persistence unit). I would like to resolve the DME before back porting the "jar-file" (WildFly) bug fix. I didn't see this behaviour in my ORM 4.2.x testing (with EAP). By the way, the getPersistenceUnitRootUrl is the test.ear. test.ear contents: lib test-entities.jar META-INF application.xml MANIFEST.MF persistence.xml test-ejb.jar persistence.xml contents: <persistence-unit name="jboss-eap-hibernate" transaction-type="JTA"> <jar-file>lib/test-entities.jar</jar-file> <exclude-unlisted-classes/> </persistence-unit> test-entities.jar contents: META-INF Event.hbm.xml EventManager entity class Event entity class Event.hbm.xml contents: <hibernate-mapping package="support.jboss.ejb.entity"> <sql-query name="EventManager.MyEvents"> <load-collection alias="manages" role="EventManager.manages" /> SELECT * FROM EVENT e where e.manager = ? </sql-query> Thanks, Scott