I think that this is bug in Spring. It has been compiled against Hibernate ORM 5.2.

In Hibernate ORM 5.1 exists method getProperties that returns java.util.Properties. In Hibernate ORM 5.2 there is no getProperties method defined in SessionFactoryImplementor but there is one inherited from javax.persistence.EntityManagerFactory and this one is returning java.util.Map . I have to check little bit further, but I believe that this is cause of (my) problem.