diff --git a/src/ng/interval.js b/src/ng/interval.js
index 1e58981a91e5..1212ee5317f0 100644
--- a/src/ng/interval.js
+++ b/src/ng/interval.js
@@ -174,7 +174,7 @@ function $IntervalProvider() {
       * @description
       * Cancels a task associated with the `promise`.
       *
-      * @param {promise} promise returned by the `$interval` function.
+      * @param {Promise=} promise returned by the `$interval` function.
       * @returns {boolean} Returns `true` if the task was successfully canceled.
       */
     interval.cancel = function(promise) {