diff --git a/index.php b/index.php
index f8db16f..ec062c7 100644
--- a/index.php
+++ b/index.php
@@ -127,7 +127,7 @@ if($lang == 'zh' || $lang == 'pt' ){
 	$lang = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 5);
 }
 
-$acceptLang = ['de','es','it','zh-CN','nl','pl','el','pt-BR','ru'];
+$acceptLang = ['de','es','it','zh-CN','nl','pl','el','pt-BR','ru','cs'];
 $lang = in_array($lang, $acceptLang) ? $lang : 'en';
 $lang = strtolower($lang);
 require_once "lang/{$lang}.php";