diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6896ecc..b5997f3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,9 @@ and this project adheres to [Semantic Versioning].
 [Keep a Changelog]: https://keepachangelog.com/en/1.0.0/
 [Semantic Versioning]: https://semver.org/spec/v2.0.0.html
 
+## [4.6.4] - 2025-11-24
+- Add Subscription Set ID key to Activity
+
 ## [4.6.3] - 2025-09-01
 - Remove future dependency to resolve vulnerability issues
 
diff --git a/chartmogul/version.py b/chartmogul/version.py
index de3842d..425b9ff 100644
--- a/chartmogul/version.py
+++ b/chartmogul/version.py
@@ -1 +1 @@
-__version__ = "4.6.3"
+__version__ = "4.6.4"