diff --git a/src/ol/interaction/doubleclickzoominteraction.js b/src/ol/interaction/doubleclickzoominteraction.js
index a9cf643b87..a874369363 100644
--- a/src/ol/interaction/doubleclickzoominteraction.js
+++ b/src/ol/interaction/doubleclickzoominteraction.js
@@ -18,13 +18,13 @@ goog.require('ol.interaction.Interaction');
  */
 ol.interaction.DoubleClickZoom = function(opt_options) {
 
-  var options = goog.isDef(opt_options) ? opt_options : {};
+  var options = opt_options ? opt_options : {};
 
   /**
    * @private
    * @type {number}
    */
-  this.delta_ = goog.isDef(options.delta) ? options.delta : 1;
+  this.delta_ = options.delta ? options.delta : 1;
 
   goog.base(this, {
     handleEvent: ol.interaction.DoubleClickZoom.handleEvent
@@ -34,7 +34,7 @@ ol.interaction.DoubleClickZoom = function(opt_options) {
    * @private
    * @type {number}
    */
-  this.duration_ = goog.isDef(options.duration) ? options.duration : 250;
+  this.duration_ = options.duration ? options.duration : 250;
 
 };
 goog.inherits(ol.interaction.DoubleClickZoom, ol.interaction.Interaction);