MapMessages that are not annotated as such, are handled as ObjectMessages by the consumer instead

If the annotation type "x-opt-jms-msg-type" is missing from the message (e.g. the message was created by the old qpid amqp 1.0 client) and this message is supposed to be a MapMessage, then the consumer will create an ObjectMessage instead.

This is due to AmqpJmsMessageBuilder.createWithoutAnnotation() not handling the MapMessage case, which ends up creating an ObjectMessage instead.