diff --git a/index.html b/index.html
index 35e35b6fbbb19fa392b00c6918f1d2963977842b..3013b72b044964fdb18bdc7bf50eae9044ab8475 100644
--- a/index.html
+++ b/index.html
@@ -16,7 +16,7 @@
     <nav>
       <h1>Sort Lines</h1>
       <a id="logo" class="cursordefault" href="/"><img src="../Simpel.png" alt="simpel icon" height="48" width="48"></a>
-      <a id="github" href="https://github.com/SimpelMe/sort-lines" target="_blank" title="watch source code">
+      <a id="github" href="https://github.com/SimpelMe/sort-lines" target="_blank" rel="noopener noreferrer" title="watch source code">
         <img id="github-cat" src="../github-cat-white.png" alt="github logo">
       </a>
     </nav>