diff --git a/assets/templates/_header.phtml b/assets/templates/_header.phtml
index ecf8755..f419bbf 100644
--- a/assets/templates/_header.phtml
+++ b/assets/templates/_header.phtml
@@ -6,6 +6,7 @@
 
     <title><?= $title ?? 'PHP Apprentice' ?></title>
     <meta name="description" content="<?= $description ?? 'A site for learning how to use PHP'?>">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
 
     <link rel="stylesheet" href="/css/site.css">
     <link rel="icon" href="/favicon-32.png">