diff --git a/src/Angular.js b/src/Angular.js
index 8a14b6aa..da1bf226 100644
--- a/src/Angular.js
+++ b/src/Angular.js
@@ -220,6 +220,7 @@ function setHashKey(obj, h) {
  *
  * @param {Object} dst Destination object.
  * @param {...Object} src Source object(s).
+ * @returns {Object} Reference to `dst`.
  */
 function extend(dst) {
   var h = dst.$$hashKey;