diff --git a/var/Typecho/Request.php b/var/Typecho/Request.php
index dc5309ee..af2800bb 100644
--- a/var/Typecho/Request.php
+++ b/var/Typecho/Request.php
@@ -190,7 +190,7 @@ class Typecho_Request
     /**
      * 检查ua是否合法
      *
-     * @param $agent ua字符串
+     * @param string $agent ua字符串
      * @return boolean
      */
     private function _checkAgent($agent)