diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8b0bd8fb..de99a9f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [4.21.0] - 2024-10-25
+
 ### Changed
 
 - Set the `InhibitionControlPlaneUnhealthy` to be valid for all CAPI clusters, not just MCs.
@@ -3162,7 +3164,8 @@ Fix `PromtailRequestsErrors` alerts as promtail retries after some backoff so ac
 
 - Add existing rules from https://github.com/giantswarm/prometheus-meta-operator/pull/637/commits/bc6a26759eb955de92b41ed5eb33fa37980660f2
 
-[Unreleased]: https://github.com/giantswarm/prometheus-rules/compare/v4.20.0...HEAD
+[Unreleased]: https://github.com/giantswarm/prometheus-rules/compare/v4.21.0...HEAD
+[4.21.0]: https://github.com/giantswarm/prometheus-rules/compare/v4.20.0...v4.21.0
 [4.20.0]: https://github.com/giantswarm/prometheus-rules/compare/v4.19.0...v4.20.0
 [4.19.0]: https://github.com/giantswarm/prometheus-rules/compare/v4.18.0...v4.19.0
 [4.18.0]: https://github.com/giantswarm/prometheus-rules/compare/v4.17.0...v4.18.0
diff --git a/helm/prometheus-rules/Chart.yaml b/helm/prometheus-rules/Chart.yaml
index b4e79994..c2423678 100644
--- a/helm/prometheus-rules/Chart.yaml
+++ b/helm/prometheus-rules/Chart.yaml
@@ -5,7 +5,7 @@ home: https://github.com/giantswarm/prometheus-rules
 icon: https://s.giantswarm.io/app-icons/1/png/default-app-light.png
 name: prometheus-rules
 appVersion: '0.1.0'
-version: '4.20.0'
+version: '4.21.0'
 annotations:
   application.giantswarm.io/team: "atlas"
   config.giantswarm.io/version: 1.x.x