Incorrect signature of ErrorEvent constructor

[cronon]

TypeScript Version: 2.1.1 / nightly (2.2.0-dev.201xxxxx)

Expected behavior:
ErrorEvent constructor should have params accorditng to the spec
https://html.spec.whatwg.org/multipage/webappapis.html#the-errorevent-interface

interface ErrorEventInit extends EventInit {
  message?: string;
  filename?: string;
  lineno?: number;
  conlno?: number;
  error?: any;
}
declare var ErrorEvent: {
    prototype: ErrorEvent;
    new(type: string, errorEventInitDict?: ErrorEventInit): ErrorEvent;
}

Actual behavior:
In lb.d.ts https://github.com/Microsoft/TypeScript/blob/master/lib/lib.d.ts#L7903
ErrorEvent constructor doesn't have any params.