diff --git a/module/upgrade/lang/zh-cn.php b/module/upgrade/lang/zh-cn.php
index b1d19eec1f..3259f92769 100644
--- a/module/upgrade/lang/zh-cn.php
+++ b/module/upgrade/lang/zh-cn.php
@@ -78,4 +78,4 @@ $lang->upgrade->fromVersions['5_0_beta2'] = '5.0.beta2';
 $lang->upgrade->fromVersions['5_0']       = '5.0';
 $lang->upgrade->fromVersions['5_1']       = '5.1';
 $lang->upgrade->fromVersions['5_2']       = '5.2';
-$lang->upgrade->fromVersions['5_2_1']     = '5.2_1';
+$lang->upgrade->fromVersions['5_2_1']     = '5.2.1';
diff --git a/module/upgrade/lang/zh-tw.php b/module/upgrade/lang/zh-tw.php
index ed3845e030..e2d6523ac3 100644
--- a/module/upgrade/lang/zh-tw.php
+++ b/module/upgrade/lang/zh-tw.php
@@ -78,4 +78,4 @@ $lang->upgrade->fromVersions['5_0_beta2'] = '5.0.beta2';
 $lang->upgrade->fromVersions['5_0']       = '5.0';
 $lang->upgrade->fromVersions['5_1']       = '5.1';
 $lang->upgrade->fromVersions['5_2']       = '5.2';
-$lang->upgrade->fromVersions['5_2_1']     = '5.2_1';
+$lang->upgrade->fromVersions['5_2_1']     = '5.2.1';
diff --git a/www/upgrade.php b/www/upgrade.php
index 0ce2755eaf..36d7b08c31 100644
--- a/www/upgrade.php
+++ b/www/upgrade.php
@@ -38,7 +38,7 @@ $app->setDebug();
 
 /* Check the installed version is the latest or not. */
 $config->installedVersion = $common->loadModel('setting')->getVersion();
-if(!$_SERVER['HTTP_X_REQUESTED_WITH'] and version_compare($config->version, $config->installedVersion) <= 0) die(header('location: index.php'));
+if(!empty($_SERVER['HTTP_X_REQUESTED_WITH']) and version_compare($config->version, $config->installedVersion) <= 0) die(header('location: index.php'));
 
 /* Run it. */
 $app->parseRequest();