Include Header File That Contains base_url()

[eluser]TexMax007[/eluser]
Hello All,

Problem:

Editing error_404.php to match the layout of my site, I'm trying to include two files before the main content of the page. These files are called header.php and main_menu.php.

Code:

<?php

$path = APPPATH . DIRECTORY_SEPARATOR . 'views' . DIRECTORY_SEPARATOR . 'includes' . DIRECTORY_SEPARATOR;

include_once(realpath($path . 'header.php'));
include_once(realpath($path . 'main_menu.php'));

?>
... More HTML here

It's finding the file correctly, but stopping the render when it reaches the first occurance of base_url() in my header.php

The error_log on my server says

Call to undefined function base_url() in ... header.php on line 19

It's not acceptable to remove the base_url()'s in either of these files.

Is there any way to fix this?

Thanks,

Max