kobogian hitis Thanks for report. I think it's ok. ClassHierarchyComparator is only used in ProxyFactory to sort additional interfaces a proxy class implements. I agree that it will not sort classes consistently but I believe it's not the purpose. The point is to always have subclasses before superclasses. E.g. if the list contains: Foo extends Bar, Baz extends Bar and Bar, then the only important thing is to have Foo and Baz before Bar (i.e. processed first).