diff --git a/content/master.blade.php b/content/master.blade.php
index 25d1ed4..5640c06 100644
--- a/content/master.blade.php
+++ b/content/master.blade.php
@@ -1,3 +1,4 @@
+<!DOCTYPE html>
 <html lang="{{ str_replace('_', '-', app()->getLocale()) }}">
     <head>
         <meta charset="utf-8">
