diff --git a/IPython/html/static/notebook/js/kernelselector.js b/IPython/html/static/notebook/js/kernelselector.js
index e25ed2b..d9711aa 100644
--- a/IPython/html/static/notebook/js/kernelselector.js
+++ b/IPython/html/static/notebook/js/kernelselector.js
@@ -273,7 +273,7 @@ define([
 
     KernelSelector.prototype.new_notebook = function (kernel_name) {
         
-        var w = window.open(undefined, IPython._target);
+        var w = window.open('', IPython._target);
         // Create a new notebook in the same path as the current
         // notebook's path.
         var that = this;
diff --git a/IPython/html/static/notebook/js/menubar.js b/IPython/html/static/notebook/js/menubar.js
index a7990ed..41a47e7 100644
--- a/IPython/html/static/notebook/js/menubar.js
+++ b/IPython/html/static/notebook/js/menubar.js
@@ -76,7 +76,7 @@ define([
             notebook_path
         ) + "?download=" + download.toString();
         
-        var w = window.open(undefined, IPython._target);
+        var w = window.open('', IPython._target);
         if (this.notebook.dirty) {
             this.notebook.save_notebook().then(function() {
                 w.location = url;
diff --git a/IPython/html/static/notebook/js/notebook.js b/IPython/html/static/notebook/js/notebook.js
index 09eec9c..5f572ad 100644
--- a/IPython/html/static/notebook/js/notebook.js
+++ b/IPython/html/static/notebook/js/notebook.js
@@ -2043,7 +2043,7 @@ define(function (require) {
     Notebook.prototype.copy_notebook = function () {
         var that = this;
         var base_url = this.base_url;
-        var w = window.open(undefined, IPython._target);
+        var w = window.open('', IPython._target);
         var parent = utils.url_path_split(this.notebook_path)[0];
         this.contents.copy(this.notebook_path, parent).then(
             function (data) {
diff --git a/IPython/html/static/tree/js/notebooklist.js b/IPython/html/static/tree/js/notebooklist.js
index c7341ba..0065143 100644
--- a/IPython/html/static/tree/js/notebooklist.js
+++ b/IPython/html/static/tree/js/notebooklist.js
@@ -73,7 +73,7 @@ define([
         if (!NotebookList._bound_singletons) {
             NotebookList._bound_singletons = true;
             $('#new-file').click(function(e) {
-                var w = window.open(undefined, IPython._target);
+                var w = window.open('', IPython._target);
                 that.contents.new_untitled(that.notebook_path || '', {type: 'file', ext: '.txt'}).then(function(data) {
                     var url = utils.url_join_encode(
                         that.base_url, 'edit', data.path