diff --git a/CHANGELOG.md b/CHANGELOG.md
index 11984b6..d6b6832 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,7 @@ This document outlines major changes between releases.
 - Place billing metrics to separate url path (TrueCloudLab#26)
 - Add generated deb builder files to .gitignore, and fix typo (TrueCloudLab#28)
 - Limit number of objects to delete at one time (TrueCloudLab#37) 
+- CompleteMultipartUpload handler now sends whitespace characters to keep alive client's connection (#60)
 
 ## [0.26.0] - 2022-12-28
 
diff --git a/docs/aws_s3_compat.md b/docs/aws_s3_compat.md
index e7712c4..4bde43a 100644
--- a/docs/aws_s3_compat.md
+++ b/docs/aws_s3_compat.md
@@ -71,7 +71,9 @@ For now there are some limitations:
 
 ## Multipart
 
-Should be supported soon.
+CompleteMultipartUpload operations may take long time to complete. Gateway
+sends whitespace characters to keep connection with the client alive. In this
+case, gateway is unable to set proper HTTP headers like `X-Amz-Version-Id`.
 
 |    | Method                  | Comments |
 |----|-------------------------|----------|