Scott Marlow - Does WildFly actually check that the named provider is "available" itself, rather than delegating the calls to the actual PersistenceProviders loaded? IIRC the issue in WildFLy was related to that. Again, Hibernate's org.hibernate.jpa.HibernatePersistenceProvider knows to accept <provider>org.hibernate.ejb.HibernatePersistence</provider>. The only time I can see org.hibernate.ejb.HibernatePersistence not being listed as a provider via META-INF/services/javax.persistence.spi.PersistenceProvider is if the environment (WildFly/Jipijapa) forces that issue.