Server-side includes for PHP files in virtual folders using nginx

I am able to to an include on any filetype if the folder the file is in is non-virtual.

If it is a virtual directory using the include directive for example, it does not work on the PHP files:

...

location /common/ {
    ssi on;
    alias "Z:/My Website/My Custom Common/";
}

If test.php was in the root of the server, the include would work.

Here is my PHP block in nginx.conf:

location ~ \.php$ {
    ssi on;
    fastcgi_pass 127.0.0.1:9000;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include fastcgi_params;
    fastcgi_intercept_errors on;
}