Work with interfaces and abstract classes
As a workaround, RESTEasy allows you to use the JAXB annotation @XmlSeeAlso on the interface to correct the problem. (NOTE, this will not work with manual, hand-coded JAXB). @XmlSeeAlso(RealFoo.class) public interface IFoo {} The extra @XmlSeeAlso on IFoo allows RESTEasy to create a JAXBContext that knows how to unmarshal RealFoo instances.