diff --git a/src/ol/interaction/dragpaninteraction.js b/src/ol/interaction/dragpaninteraction.js
index 66f0a5d1e1..ae78fc37ad 100644
--- a/src/ol/interaction/dragpaninteraction.js
+++ b/src/ol/interaction/dragpaninteraction.js
@@ -28,7 +28,7 @@ ol.interaction.DragPan = function(opt_options) {
     handleUpEvent: ol.interaction.DragPan.handleUpEvent_
   });
 
-  var options = goog.isDef(opt_options) ? opt_options : {};
+  var options = opt_options ? opt_options : {};
 
   /**
    * @private
@@ -51,7 +51,7 @@ ol.interaction.DragPan = function(opt_options) {
    * @private
    * @type {ol.events.ConditionType}
    */
-  this.condition_ = goog.isDef(options.condition) ?
+  this.condition_ = options.condition ?
       options.condition : ol.events.condition.noModifierKeys;
 
   /**
@@ -109,7 +109,7 @@ ol.interaction.DragPan.handleUpEvent_ = function(mapBrowserEvent) {
       var distance = this.kinetic_.getDistance();
       var angle = this.kinetic_.getAngle();
       var center = view.getCenter();
-      goog.asserts.assert(goog.isDef(center), 'center should be defined');
+      goog.asserts.assert(center !== undefined, 'center should be defined');
       this.kineticPreRenderFn_ = this.kinetic_.pan(center);
       map.beforeRender(this.kineticPreRenderFn_);
       var centerpx = map.getPixelFromCoordinate(center);