When mapping document fragments in jaxrpc, the spec recommends mapping to javax.xml.soap.SOAPElement. JBoss maps this as a org.w3c.dom.Element (a superclass), but you are unable to specify javax.xml.soap.SOAPElement in the mapping file. The fix may be in org.apache.axis.message.RPCHandler.onStartChild method, which checks if destClass.isAssignableFrom(org.w3c.dom.Element.class) when it should should probably check if destClass.isAssignableFrom(javax.xml.soap.SOAPElement)