diff --git a/src/ol/source/imagecanvassource.js b/src/ol/source/imagecanvassource.js
index d76e7c7adc..16e390ea17 100644
--- a/src/ol/source/imagecanvassource.js
+++ b/src/ol/source/imagecanvassource.js
@@ -23,7 +23,8 @@ ol.source.ImageCanvas = function(options) {
     logo: options.logo,
     projection: options.projection,
     resolutions: options.resolutions,
-    state: options.state
+    state: goog.isDef(options.state) ?
+        /** @type {ol.source.State} */ (options.state) : undefined
   });
 
   /**
diff --git a/src/ol/source/imagesource.js b/src/ol/source/imagesource.js
index ed438518d9..573217f95e 100644
--- a/src/ol/source/imagesource.js
+++ b/src/ol/source/imagesource.js
@@ -14,7 +14,7 @@ goog.require('ol.source.Source');
  *            logo: (string|olx.LogoOptions|undefined),
  *            projection: ol.proj.ProjectionLike,
  *            resolutions: (Array.<number>|undefined),
- *            state: (ol.source.State|string|undefined)}}
+ *            state: (ol.source.State|undefined)}}
  */
 ol.source.ImageOptions;
 
diff --git a/src/ol/source/source.js b/src/ol/source/source.js
index b02f016cb0..591b45730f 100644
--- a/src/ol/source/source.js
+++ b/src/ol/source/source.js
@@ -24,7 +24,7 @@ ol.source.State = {
  * @typedef {{attributions: (Array.<ol.Attribution>|undefined),
  *            logo: (string|olx.LogoOptions|undefined),
  *            projection: ol.proj.ProjectionLike,
- *            state: (ol.source.State|string|undefined)}}
+ *            state: (ol.source.State|undefined)}}
  */
 ol.source.SourceOptions;
 
@@ -69,7 +69,7 @@ ol.source.Source = function(options) {
    * @type {ol.source.State}
    */
   this.state_ = goog.isDef(options.state) ?
-      /** @type {ol.source.State} */ (options.state) : ol.source.State.READY;
+      options.state : ol.source.State.READY;
 
 };
 goog.inherits(ol.source.Source, ol.Observable);
diff --git a/src/ol/source/tileimagesource.js b/src/ol/source/tileimagesource.js
index 6ff5a755bb..ffacae74f1 100644
--- a/src/ol/source/tileimagesource.js
+++ b/src/ol/source/tileimagesource.js
@@ -29,7 +29,8 @@ ol.source.TileImage = function(options) {
     logo: options.logo,
     opaque: options.opaque,
     projection: options.projection,
-    state: options.state,
+    state: goog.isDef(options.state) ?
+        /** @type {ol.source.State} */ (options.state) : undefined,
     tileGrid: options.tileGrid,
     tilePixelRatio: options.tilePixelRatio
   });
diff --git a/src/ol/source/tilesource.js b/src/ol/source/tilesource.js
index 693a33cc37..a29f5358ea 100644
--- a/src/ol/source/tilesource.js
+++ b/src/ol/source/tilesource.js
@@ -17,7 +17,7 @@ goog.require('ol.tilegrid.TileGrid');
  *            opaque: (boolean|undefined),
  *            tilePixelRatio: (number|undefined),
  *            projection: ol.proj.ProjectionLike,
- *            state: (ol.source.State|string|undefined),
+ *            state: (ol.source.State|undefined),
  *            tileGrid: (ol.tilegrid.TileGrid|undefined)}}
  */
 ol.source.TileOptions;
diff --git a/src/ol/source/vectorsource.js b/src/ol/source/vectorsource.js
index 7353292b24..dc8dea8414 100644
--- a/src/ol/source/vectorsource.js
+++ b/src/ol/source/vectorsource.js
@@ -56,7 +56,8 @@ ol.source.Vector = function(opt_options) {
     attributions: options.attributions,
     logo: options.logo,
     projection: options.projection,
-    state: options.state
+    state: goog.isDef(options.state) ?
+        /** @type {ol.source.State} */ (options.state) : undefined
   });
 
   /**