Yes this is a limitation. The only workaround you could do right now is to create a dummy method that had all known subtypes in it's signature. In order to support XmlSeeAlso we just need to upgrade to JAXB 2.1. I have created a request for this for the 2.0 release. Until then you could try doing this yourself. Although I should warn you that while it should be compatible we have not done thorough testing on it. http://jira.jboss.com/jira/browse/JBWS-1591 -Jason View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4032452#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...