Accessing index.php 403 Forbidden

I'm working on a website and trying to make php includes work. The website is running on LAMP with php7. I have changed the index.html to index.php and added this code to include the header:

<?php include 'include/header.php'; ?>

The ownergroup is set right and the file permissions on 644. But when i go to: http://localhost/pages/index.php I get this 403 Forbidden error. It seems like i can't see php files.