diff --git a/IPython/html/static/tree/js/notebooklist.js b/IPython/html/static/tree/js/notebooklist.js
index a1e3c6c78..e208fe029 100644
--- a/IPython/html/static/tree/js/notebooklist.js
+++ b/IPython/html/static/tree/js/notebooklist.js
@@ -281,7 +281,7 @@ var IPython = (function (IPython) {
 
     NotebookList.prototype.add_shutdown_button = function (item, session) {
         var that = this;
-        var shutdown_button = $("<button/>").text("Shutdown").addClass("btn btn-mini").
+        var shutdown_button = $("<button/>").text("Shutdown").addClass("btn btn-mini btn-danger").
             click(function (e) {
                 var settings = {
                     processData : false,