diff --git a/src/ol/interaction/snapinteraction.js b/src/ol/interaction/snapinteraction.js
index 898bd0d15a..9eca618070 100644
--- a/src/ol/interaction/snapinteraction.js
+++ b/src/ol/interaction/snapinteraction.js
@@ -27,8 +27,8 @@ goog.require('ol.structs.RBush');
 /**
  * @classdesc
  * Handles snapping of vector features while modifying or drawing them.  The
- * features can come from a {@link ol.source.Vector}, a {@link ol.Collection}
- * or a plain array. Any interaction object that allows the user to interact
+ * features can come from a {@link ol.source.Vector} or {@link ol.Collection}
+ * Any interaction object that allows the user to interact
  * with the features using the mouse can benefit from the snapping, as long
  * as it is added before.
  *
@@ -94,6 +94,15 @@ ol.interaction.Snap = function(opt_options) {
    */
   this.indexedFeaturesExtents_ = {};
 
+  /**
+   * If a feature geometry changes while a pointer drag|move event occurs, the
+   * feature doesn't get updated right away.  It will be at the next 'pointerup'
+   * event fired.
+   * @type {Object.<number, ol.Feature>}
+   * @private
+   */
+  this.pendingFeatures_ = {};
+
   /**
    * Used for distance sorting in sortByDistance_
    * @type {ol.Coordinate}
@@ -154,7 +163,8 @@ ol.interaction.Snap.prototype.addFeature = function(feature, opt_listen) {
   var segmentWriter = this.SEGMENT_WRITERS_[geometry.getType()];
   if (goog.isDef(segmentWriter)) {
     var feature_uid = goog.getUid(feature);
-    this.indexedFeaturesExtents_[feature_uid] = geometry.getExtent();
+    this.indexedFeaturesExtents_[feature_uid] = geometry.getExtent(
+        ol.extent.createEmpty());
     segmentWriter.call(this, feature, geometry);
 
     if (listen) {
@@ -174,16 +184,6 @@ goog.exportProperty(
     ol.interaction.Snap.prototype.addFeature);
 
 
-/**
- * If a feature geometry changes while a pointer drag|move event occurs, the
- * feature doesn't get updated right away.  It will be at the next 'pointerup'
- * event fired.
- * @type {Object.<number, ol.Feature>}
- * @private
- */
-ol.interaction.Snap.prototype.pendingFeatures_ = null;
-
-
 /**
  * @param {ol.Feature} feature Feature.
  * @private
@@ -602,9 +602,11 @@ ol.interaction.Snap.handleEvent_ = function(evt) {
  * @private
  */
 ol.interaction.Snap.handleUpEvent_ = function(evt) {
-  goog.array.forEach(goog.object.getValues(this.pendingFeatures_),
-      this.updateFeature_, this);
-  this.pendingFeatures_ = {};
+  var featuresToUpdate = goog.object.getValues(this.pendingFeatures_);
+  if (featuresToUpdate.length) {
+    goog.array.forEach(featuresToUpdate, this.updateFeature_, this);
+    this.pendingFeatures_ = {};
+  }
   return false;
 };