Mouse events on masked containers

Hello everyone! I'm currently working with the latest version of PIXI.js (4.1.1) and have a problem with masked container.

Code example:

var stage = new PIXI.Container(),
 mask = new PIXI.Graphics(),
 gameStage = new PIXI.Container();

mask.drawRect(0, 0, 1100, 630);
mask.endFill();
gameStage.mask = mask;

stage.addChild(rectangle);
stage.addChild(gameStage);

gameStage contains a list of interactive buttons but I can't interact with any element behind the mask.