ClassCastException when retrieving the result of an asynchronous EJB method execution in EAP 6

Issue

We have an EJB in an EAR that uses asynchronous methods and it is consumed by another WAR deployment:

@EJB(lookup="java:global/testejb/testejb-ejb/AsyncService!rh.test.AsyncEJB")
private AsyncEJB asyncEJB;

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Future<ReturnObject> futro = asyncEJB.testAsync();
        ReturnObject ro; 
        try {
                // this line throws the CCE
                ro = futro.get();
        }   
        catch (InterruptedException e) {
                printResponse(resp, e.getMessage());
                return;
        }   
        catch (ExecutionException e) {
                printResponse(resp, e.getMessage());
                return;
        }
}

When trying to retrieve the EJB invocation using Future.get, we have ClassCastException error:

JBWEB000236: Servlet.service() for servlet rh.test.AsyncServlet threw exception: java.lang.ClassCastException: rh.test.ReturnObject cannot be cast to rh.test.ReturnObject