diff --git a/config/example.json b/config/example.json
index 5ed49aa7da..e5ac3aaf7b 100644
--- a/config/example.json
+++ b/config/example.json
@@ -31,6 +31,7 @@
       "*"
     ],
     "jscomp_off": [
+      "unnecessaryCasts",
       "useOfGoogBase",
       "lintChecks",
       "analyzerChecks",
diff --git a/config/examples-all.json b/config/examples-all.json
index fb3c2d2874..40d452b4b3 100644
--- a/config/examples-all.json
+++ b/config/examples-all.json
@@ -32,6 +32,7 @@
       "*"
     ],
     "jscomp_off": [
+      "unnecessaryCasts",
       "useOfGoogBase",
       "lintChecks",
       "analyzerChecks"
diff --git a/config/ol.json b/config/ol.json
index 1a4071d6a0..37039fac71 100644
--- a/config/ol.json
+++ b/config/ol.json
@@ -21,6 +21,7 @@
       "*"
     ],
     "jscomp_off": [
+      "unnecessaryCasts",
       "useOfGoogBase",
       "lintChecks",
       "analyzerChecks"
diff --git a/package.json b/package.json
index 7b58d9f216..1343b30b9c 100644
--- a/package.json
+++ b/package.json
@@ -32,7 +32,7 @@
   "dependencies": {
     "async": "1.5.2",
     "browserify": "13.0.0",
-    "closure-util": "1.12.0",
+    "closure-util": "1.13.0",
     "derequire": "2.0.3",
     "fs-extra": "0.26.6",
     "glob": "6.0.4",
diff --git a/src/ol/animation.js b/src/ol/animation.js
index 55d4e512ea..4e9833b3fb 100644
--- a/src/ol/animation.js
+++ b/src/ol/animation.js
@@ -24,6 +24,7 @@ ol.animation.bounce = function(options) {
       /**
        * @param {ol.Map} map Map.
        * @param {?olx.FrameState} frameState Frame state.
+       * @return {boolean} Run this function in the next frame.
        */
       function(map, frameState) {
         if (frameState.time < start) {
@@ -62,6 +63,7 @@ ol.animation.pan = function(options) {
       /**
        * @param {ol.Map} map Map.
        * @param {?olx.FrameState} frameState Frame state.
+       * @return {boolean} Run this function in the next frame.
        */
       function(map, frameState) {
         if (frameState.time < start) {
@@ -103,6 +105,7 @@ ol.animation.rotate = function(options) {
       /**
        * @param {ol.Map} map Map.
        * @param {?olx.FrameState} frameState Frame state.
+       * @return {boolean} Run this function in the next frame.
        */
       function(map, frameState) {
         if (frameState.time < start) {
@@ -146,6 +149,7 @@ ol.animation.zoom = function(options) {
       /**
        * @param {ol.Map} map Map.
        * @param {?olx.FrameState} frameState Frame state.
+       * @return {boolean} Run this function in the next frame.
        */
       function(map, frameState) {
         if (frameState.time < start) {