abstract class IdeaBugTest<M extends IdeaBugTest.Mapping> { static class Mapping {} } class BugTestSub extends IdeaBugTest<<error descr="Mapping is not accessible in current context">BugTestSub.SubMapping</error>> { public abstract static class SubMapping extends Mapping {} } class BugTestSub1 extends IdeaBugTest<BugTestSub1.SubMapping> { public abstract static class SubMapping extends IdeaBugTest.Mapping {} //fqn here } class AbstractSettings { interface State {} } interface SomeInterface<T> {} class Settings extends AbstractSettings implements SomeInterface<Settings.MyState> { static class MyState implements State {} }