diff --git a/IPython/html/static/notebook/js/widgetmanager.js b/IPython/html/static/notebook/js/widgetmanager.js
index 5dbdd35..839be37 100644
--- a/IPython/html/static/notebook/js/widgetmanager.js
+++ b/IPython/html/static/notebook/js/widgetmanager.js
@@ -23,7 +23,7 @@
     // elsewhere.
     define(["underscore",
              "backbone",
-            ], function (Underscore, Backbone) {
+            ], function (_, Backbone) {
 
         //--------------------------------------------------------------------
         // WidgetManager class
diff --git a/IPython/html/static/notebook/js/widgets/widget.js b/IPython/html/static/notebook/js/widgets/widget.js
index d2857f0..9d05c57 100644
--- a/IPython/html/static/notebook/js/widgets/widget.js
+++ b/IPython/html/static/notebook/js/widgets/widget.js
@@ -17,7 +17,7 @@
 define(["notebook/js/widgetmanager",
         "underscore",
         "backbone"], 
-function(WidgetManager, Underscore, Backbone){
+function(WidgetManager, _, Backbone){
 
     var WidgetModel = Backbone.Model.extend({
         constructor: function (widget_manager, model_id, comm) {