diff --git a/gems/aws-sdk-glacier/CHANGELOG.md b/gems/aws-sdk-glacier/CHANGELOG.md
index 9e3152d4a7f..88779e6fbfe 100644
--- a/gems/aws-sdk-glacier/CHANGELOG.md
+++ b/gems/aws-sdk-glacier/CHANGELOG.md
@@ -1,13 +1,15 @@
 Unreleased Changes
 ------------------
 
+* Issue - Fix `complete_multipart_upload` to calculate a Tree Hash checksum. (#2890)
+
 1.54.0 (2023-07-11)
 ------------------
 
 * Feature - Code Generated Changes, see `./build_tools` or `aws-sdk-core`'s CHANGELOG.md for details.
 
 1.53.0 (2023-07-06)
-------------------
+------------------  
 
 * Feature - Code Generated Changes, see `./build_tools` or `aws-sdk-core`'s CHANGELOG.md for details.
 
diff --git a/gems/aws-sdk-glacier/lib/aws-sdk-glacier/plugins/checksums.rb b/gems/aws-sdk-glacier/lib/aws-sdk-glacier/plugins/checksums.rb
index 756d7aca9ae..1338deb3be4 100644
--- a/gems/aws-sdk-glacier/lib/aws-sdk-glacier/plugins/checksums.rb
+++ b/gems/aws-sdk-glacier/lib/aws-sdk-glacier/plugins/checksums.rb
@@ -28,6 +28,7 @@ module Plugins
       class Checksums < Seahorse::Client::Plugin
 
         CHECKSUM_OPERATIONS = [
+          :complete_multipart_upload,
           :upload_archive,
           :upload_multipart_part,
         ]