In JmsServiceExporter, following code means that JMSServiceExporter.onMessage can be called in another thread before super.afterProperties initializes the marshaller, leading to "MQJMS1034E MessageListener threw: java.lang.NullPointerException" error ... // do we have a destination specified, if so consume if (destination != null) { Session session = producer.getSession(); consumer = session.createConsumer(destination); consumer.setMessageListener(this); } super.afterPropertiesSet(); } Possible solution may be to call super.afterPropertiesSet() before calling consumer.setMessageListener(this), this seems to be where the thread is being created by Websphere MQ implementation