diff --git a/app/index.php b/app/index.php
index e9e351f629..20f6433765 100644
--- a/app/index.php
+++ b/app/index.php
@@ -47,10 +47,10 @@
     ?>
 
 
-    <link rel="stylesheet" href="https://storage.googleapis.com/code.getmdl.io/1.1.2/material.blue_grey-amber.min.css" />
-    <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
-    <link rel='stylesheet' href='https://fonts.googleapis.com/css?family=Roboto:400,700'>
-    <script src="//storage.googleapis.com/code.getmdl.io/1.1.2/material.min.js"></script>
+    <link rel="stylesheet" crossorign="anonymous" integrity="sha256-cwNKGvxkCC8PXO3zGjY2oHaU3TTUG8e+cNHE8uC+B+E=" href="https://storage.googleapis.com/code.getmdl.io/1.1.2/material.blue_grey-amber.min.css" />
+    <link rel="stylesheet" crossorign="anonymous" integrity="sha256-84ef1bXQjXdmG+bNbSbO0Y+4fsZP2/ErjAn4GDn+D44=" href="https://fonts.googleapis.com/icon?family=Material+Icons">
+    <link rel='stylesheet' crossorign="anonymous" integrity="sha256-8MVHE8E/ZgANWGKD1HYQ9Ia4vDzIF9OculKcF1vK1JI=" href='https://fonts.googleapis.com/css?family=Roboto:400,700'>
+    <script crossorign="anonymous" integrity="sha256-s0bGtNviXkzZc69iS+m80CI5K83r7r5sA4+2/NhZ8Zw=" src="//storage.googleapis.com/code.getmdl.io/1.1.2/material.min.js"></script>
     <!-- inject:css -->
     <!-- endinject -->