diff --git a/core/layout/blank.php b/core/layout/blank.php
index ed8baa32..789b1af6 100644
--- a/core/layout/blank.php
+++ b/core/layout/blank.php
@@ -1,6 +1,5 @@
-<?php $lan = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2); ?>
 <!DOCTYPE html>
-<html prefix="og: http://ogp.me/ns#" lang="<?php echo $lan;?>">
+<html prefix="og: http://ogp.me/ns#" lang="<?php echo self::$i18n;?>">
 <head>
 	<meta charset="UTF-8">
 	<meta name="viewport" content="width=device-width, initial-scale=1">
diff --git a/core/layout/light.php b/core/layout/light.php
index 82ae54fd..833cb19d 100644
--- a/core/layout/light.php
+++ b/core/layout/light.php
@@ -1,6 +1,5 @@
-<?php $lan = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2); ?>
 <!DOCTYPE html>
-<html prefix="og: http://ogp.me/ns#" lang="<?php echo $lan;?>">
+<html prefix="og: http://ogp.me/ns#" lang="<?php echo self::$i18n;?>">
 <head>
 	<meta charset="UTF-8">
 	<meta name="viewport" content="width=device-width, initial-scale=1">
diff --git a/core/layout/main.php b/core/layout/main.php
index c046975c..09575203 100644
--- a/core/layout/main.php
+++ b/core/layout/main.php
@@ -1,6 +1,5 @@
-<?php $lan = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2); ?>
 <!DOCTYPE html>
-<html prefix="og: http://ogp.me/ns#" lang="<?php echo $lan;?>">
+<html prefix="og: http://ogp.me/ns#" lang="<?php echo self::$i18n;?>">
 	<head>
 		<meta charset="UTF-8">
 		<meta name="viewport" content="width=device-width, initial-scale=1">
