It's not so much public fields as AccessType.FIELD (which may be implicit in the case that the JPA annotations are on the fields) which in turn is the case where public fields are used and getters are optional. In such instances it's inappropriate for Hibernate to use proxies, since without a getter on the call path there is nothing to trigger population of the object. The metamodel should contain enough information to allow the engine to recognize this case, but apparently not.