diff --git a/src/wp-includes/js/customize-preview-widgets.js b/src/wp-includes/js/customize-preview-widgets.js
index 92267e88fb..f9828295fc 100644
--- a/src/wp-includes/js/customize-preview-widgets.js
+++ b/src/wp-includes/js/customize-preview-widgets.js
@@ -2,8 +2,7 @@
 
 	if ( ! wp || ! wp.customize ) { return; }
 
-	var api = wp.customize,
-		OldPreview;
+	var api = wp.customize;
 
 	/**
 	 * wp.customize.WidgetCustomizerPreview
@@ -20,6 +19,8 @@
 
 		init: function () {
 			var self = this;
+
+			this.preview = api.preview;
 			this.buildWidgetSelectors();
 			this.highlightControls();
 
@@ -104,17 +105,6 @@
 		}
 	};
 
-	/**
-	 * Capture the instance of the Preview since it is private
-	 */
-	OldPreview = api.Preview;
-	api.Preview = OldPreview.extend( {
-		initialize: function( params, options ) {
-			api.WidgetCustomizerPreview.preview = this;
-			OldPreview.prototype.initialize.call( this, params, options );
-		}
-	} );
-
 	$(function () {
 		var settings = window._wpWidgetCustomizerPreviewSettings;
 		if ( ! settings ) {