diff --git a/index.html b/index.html
index 2d5a61b..5b37265 100644
--- a/index.html
+++ b/index.html
@@ -1,5 +1,5 @@
+<!DOCTYPE html>
 <html>
-
 <head>
   <title>ES6</title>
   <link rel="icon" type="image/png" href="favicon.png" />
@@ -9,4 +9,4 @@
   <script src="index.js"></script>
 </body>
 
-</html>
\ No newline at end of file
+</html>
