diff --git a/IPython/html/static/notebook/js/widgetmanager.js b/IPython/html/static/notebook/js/widgetmanager.js
index afd8f3f..eeff6eb 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) {
diff --git a/IPython/html/widgets/widget.py b/IPython/html/widgets/widget.py
index 1e7ff06..4cd8c19 100644
--- a/IPython/html/widgets/widget.py
+++ b/IPython/html/widgets/widget.py
@@ -79,7 +79,7 @@ class Widget(LoggingConfigurable):
     #-------------------------------------------------------------------------
     # Traits
     #-------------------------------------------------------------------------
-    model_name = Unicode('WidgetModel', help="""Name of the backbone model 
+    _model_name = Unicode('WidgetModel', help="""Name of the backbone model 
         registered in the front-end to create and sync this widget with.""")
     _view_name = Unicode(help="""Default view registered in the front-end
         to use to represent the widget.""", sync=True)
@@ -121,7 +121,7 @@ class Widget(LoggingConfigurable):
         If a Comm doesn't exist yet, a Comm will be created automagically."""
         if self._comm is None:
             # Create a comm.
-            self._comm = Comm(target_name=self.model_name)
+            self._comm = Comm(target_name=self._model_name)
             self._comm.on_msg(self._handle_msg)
             self._comm.on_close(self._close)
             Widget.widgets[self.model_id] = self