Suppose I have a remote GWT service method like this: A getA(); and a corresponding async interface method: void getA(AsyncCallback); I will probably call this like this: service.getA( new AsyncCallback() { public void onSuccess( Object result ) { A a = ( A )result; .... } ... } ); suppose I'm now refactoring the base method: ADifferentA getA(); the cast in the onSuccess is now wrong, but nothing in IDEA tells me that. I believe an inspection should warn about wrong casts in cases like this one.