diff --git a/10-dynamic-pages.md b/10-dynamic-pages.md
index e2171e8..348e4e3 100644
--- a/10-dynamic-pages.md
+++ b/10-dynamic-pages.md
@@ -9,7 +9,7 @@ Our first feature will be dynamic pages generated from [markdown](http://en.wiki
 Create a `Page` controller with the following content:
 
 ```php
-<?php
+<?php declare(strict_types = 1);
 
 namespace Example\Controllers;