In classes, super.foo() will look in superclasses only. If you want to call a default implementation from a superinterface, you need to qualify super with the interface name: Fooable.super.foo().

public interface Fooable {
    default int foo() {return 3;}
}

public class A extends Object implements Fooable {
    @Override
    public int foo() {
        //return super.foo() + 1; //error: no method foo() in java.lang.Object
        return Fooable.super.foo() + 1; //okay, returns 4
    }
}