JPA 2 has added a new attribute to the persistence-unit element. It is required but is fixed at the same time so the user doesn't have to set it explicitly. I can't seem to find a way to let JBoss XB to populate my mapped attribute with he fixed value. I always end up with null. How can I do that? PS: I can't hard code the value as the binding model is supposed to bind both JPA1 and JPA2 so null != 2.0 Here is the attribute declaration <xsd:attribute name="version" type="persistence:versionType" | fixed="2.0" use="required"/> View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4261856#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...