diff --git a/src/events.js b/src/events.js
index 86cf74cbab..80421a305d 100644
--- a/src/events.js
+++ b/src/events.js
@@ -8,6 +8,7 @@ node.EventEmitter.prototype.addListener = function (type, listener) {
     if (!this._events.hasOwnProperty(type)) this._events[type] = [];
     this._events[type].push(listener);
   }
+  return this;
 };
 
 node.EventEmitter.prototype.listeners = function (type) {