From the spec: The ejb-jar file must contain, either by inclusion or by reference, the class files of each enterprise bean as follows:
The enterprise bean class. The enterprise bean home and component interfaces. The primary key class if the bean is an entity bean. The ejb-jar file must also contain, either by inclusion or by reference, the class files for all the classes and interfaces that each enterprise bean class and the home and component interfaces depend on, except J2EE and J2SE classes. The Application Assembler must not package the stubs of the EJBHome and EJBObject interfaces in the ejb-jar file.
but, in the case of Message Driven Bean, there is no home, no component, so how can we include those files into ejb-jar file?