"Json" as controller name does not work

Well i've faced a very weird issue.

If i create a controller named "Json" and try to access it i get an "Object not found" error in my CI project. On the other hand if i give the controller another name it'll work like a charm or if i use an Uppercase first letter it will also work.

Here's my controller, filename and routes files.

Json.php

PHP Code:

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Json extends CI_Controller {
 public function index(){
   // Some code
 }
} 


Routes.php

PHP Code:

$route['(?i)json']              = 'json';
$route['(?i)json/(:any)']       = 'json/$1'; 


Any ideas?

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