diff --git a/CHANGELOG.md b/CHANGELOG.md
index 50274fa1..511a828f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # ChangeLog - Aliyun OSS SDK for PHP
 
+## v2.4.3 / 2021-08-25
+* Fixed: integer overflow in PHP5.x.
+
 ## v2.4.2 / 2021-06-04
 * Compatible with PHP8.
 * Fixed: compatible with PHP5.4.
diff --git a/src/OSS/OssClient.php b/src/OSS/OssClient.php
index 8e558bce..0922a0b7 100644
--- a/src/OSS/OssClient.php
+++ b/src/OSS/OssClient.php
@@ -3509,8 +3509,8 @@ public function setConnectTimeout($connectTimeout)
     );
     // OssClient version information
     const OSS_NAME = "aliyun-sdk-php";
-    const OSS_VERSION = "2.4.2";
-    const OSS_BUILD = "20210604";
+    const OSS_VERSION = "2.4.3";
+    const OSS_BUILD = "20210825";
     const OSS_AUTHOR = "";
     const OSS_OPTIONS_ORIGIN = 'Origin';
     const OSS_OPTIONS_REQUEST_METHOD = 'Access-Control-Request-Method';