diff --git a/static/js/services/notification-service.js b/static/js/services/notification-service.js
index ade256a63..47eddfd2b 100644
--- a/static/js/services/notification-service.js
+++ b/static/js/services/notification-service.js
@@ -196,6 +196,10 @@ function($rootScope, $interval, UserService, ApiService, StringBuilderService, P
   };
 
   notificationService.getClasses = function(notifications) {
+    if (!notifications.length) {
+      return '';
+    }
+
     var classes = [];
     for (var i = 0; i < notifications.length; ++i) {
       var notification = notifications[i];