diff --git a/install/Mysql.php b/install/Mysql.php
index dac68993..64e27b26 100644
--- a/install/Mysql.php
+++ b/install/Mysql.php
@@ -3,7 +3,7 @@
 <?php
 $engine = '';
 
-if (defined('SAE_MYSQL_DB')) {
+if (defined('SAE_MYSQL_DB') && SAE_MYSQL_DB != "app_") {
     $engine = 'SAE';
 } else if (!!getenv('HTTP_BAE_ENV_ADDR_SQL_IP')) {
     $engine = 'BAE';
diff --git a/var/Typecho/Common.php b/var/Typecho/Common.php
index 26c3e660..e631ec1f 100644
--- a/var/Typecho/Common.php
+++ b/var/Typecho/Common.php
@@ -9,7 +9,7 @@
  * @version $Id$
  */
 
-define('__TYPECHO_MB_SUPPORTED__', function_exists('mb_get_info'));
+define('__TYPECHO_MB_SUPPORTED__', function_exists('mb_get_info') && function_exists('mb_regex_encoding'));
 
 /**
  * Typecho公用方法