Error:(12, 27) TS2307: Cannot find external module 'TweenMax'. (require.js)

Hi -

the typescript file gives me the above error, the compiled javascript is fine.
So it's more of an irritation than a real problem.

My ts file:

import d3 = require('d3');
import TweenMax = require('TweenMax');

This is how the js file starts:

define(["require", "exports", 'd3', 'TweenMax', "events/event"], function (require, exports, d3, TweenMax, CustomEvent) {})

I have the definition files:

/// <reference path="../../typings/greensock/greensock.d.ts" />
/// <reference path="../../typings/d3/d3.d.ts" />

Code completion does work for TweenMax --> cmd-click takes me to the definition file.

What could cause the above error?

Thank you for your help!

Ulrich Sinn