diff --git a/CHANGELOG.md b/CHANGELOG.md
index f432e29401..076c2d9738 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # CHANGELOG
 
-## next release
+## 3.278.0 - 2023-08-10
 
 * `Aws\Multipart` - Include ChecksumAlgorithm member in Multipart Upload and Copy for flexible checksums
 * `Aws\CloudTrail` - Documentation updates for CloudTrail.
diff --git a/src/Sdk.php b/src/Sdk.php
index de624bc390..3ac8f95ed7 100644
--- a/src/Sdk.php
+++ b/src/Sdk.php
@@ -711,7 +711,7 @@
  */
 class Sdk
 {
-    const VERSION = '3.277.12';
+    const VERSION = '3.278.0';
 
     /** @var array Arguments for creating clients */
     private $args;