diff --git a/externs/olx.js b/externs/olx.js
index 22e1921606..c4a5ebb218 100644
--- a/externs/olx.js
+++ b/externs/olx.js
@@ -3138,6 +3138,7 @@ olx.interaction.DrawOptions.prototype.wrapX;
 /**
  * @typedef {{extent: (ol.Extent|undefined),
  *     boxStyle: (ol.style.Style|Array.<ol.style.Style>|ol.StyleFunction|undefined),
+ *     pixelTolerance: (number|undefined),
  *     pointerStyle: (ol.style.Style|Array.<ol.style.Style>|ol.StyleFunction|undefined),
  *     wrapX: (boolean|undefined)}}
  * @api
@@ -3159,6 +3160,14 @@ olx.interaction.ExtentOptions.prototype.extent;
  */
 olx.interaction.ExtentOptions.prototype.boxStyle;
 
+/**
+ * Pixel tolerance for considering the pointer close enough to a segment or
+ * vertex for editing. Default is `10`.
+ * @type {number|undefined}
+ * @api
+ */
+olx.interaction.ExtentOptions.prototype.pixelTolerance;
+
 /**
  * Style for the cursor used to draw the extent.
  * Defaults to ol.style.Style.createDefaultEditing()[ol.geom.GeometryType.POINT]
diff --git a/src/ol/interaction/extent.js b/src/ol/interaction/extent.js
index 4373893872..0443b5e7e4 100644
--- a/src/ol/interaction/extent.js
+++ b/src/ol/interaction/extent.js
@@ -31,7 +31,7 @@ goog.require('ol.style.Style');
  */
 ol.interaction.Extent = function(opt_options) {
 
-  var options = opt_options ? opt_options : {};
+  var options = opt_options || {};
 
   /**
    * Extent of the drawn box