Remove the myfaces-api-1.1.3.jar from your war. This jar supplies the JSF api interfaces. These interfaces are already supplied by the server. You can then override the implementation of these interfaces by including the myfaces-impl jar (like you do) or some other provider. Although a previous post recommends replacing the version of myfaces that ships with JBoss, this shouldn't be necessary. Overriding the implementation works fine. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3960062#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...