It wasn't working if the files are in the non-relative path. ``` //index.ts export {default as Foo} 'src/foo'; export {default as Foo2} 'src/foo2'; //src/foo.ts export default class Foo { bar():boolean { return true; } } //src/foo2.ts import Foo 'src/foo'; export default class Foo2 extends Foo { bar():boolean { return true; } } ```