diff --git a/qcloudcos/conf.php b/qcloudcos/conf.php
index 3a5196b..a76a389 100644
--- a/qcloudcos/conf.php
+++ b/qcloudcos/conf.php
@@ -4,7 +4,7 @@
 
 class Conf {
     // Cos php sdk version number.
-    const VERSION = 'v4.2.2';
+    const VERSION = 'v4.2.3';
     const API_COSAPI_END_POINT = 'http://region.file.myqcloud.com/files/v2/';
 
     // Please refer to http://console.qcloud.com/cos to fetch your app_id, secret_id and secret_key.