The method org.jboss.axis.message.SOAPFaultImpl.outputImpl(org.jboss.axis.encoding.SerializationContext) writes a SOAP fault out on the wire. The fault must be an instance of org.jboss.axis.AxisFault. AxisFault extends RemoteException which has a public member "detail" of type Throwable. AxisFault also has a property FaultDetails of type List. The "detail" and FaultDetails are not necessarily related, however SOAPFaultImpl will only serialize the FaultDetails if "detail" is not null. The attached patch will serialize the FaultDetails even if "detail" is null.