diff --git a/CHANGELOG.md b/CHANGELOG.md
index 722084302..426a7a416 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,24 @@
 # Change Log
 
+## [21.0.0] - 2026-04-13
+
+### Added
+
+- Ability for `run-task` to fetch arbitrary extra refs
+- Ability for Decision task to override params via Git notes
+
+### Fixed
+
+- Improved index route verification
+
+### Changed
+
+- BREAKING CHANGE: run-task and decision images now use Debian 13
+
+### Removed
+
+- BREAKING CHANGE: Removed docker-worker features: dind, privileged, loopback-audio
+
 ## [20.0.0] - 2026-03-17
 
 ### Added
diff --git a/docs/reference/migrations.rst b/docs/reference/migrations.rst
index 829b30788..e4991dfa2 100644
--- a/docs/reference/migrations.rst
+++ b/docs/reference/migrations.rst
@@ -3,6 +3,15 @@ Migration Guide
 
 This page can help when migrating Taskgraph across major versions.
 
+20.x -> 21.x
+------------
+
+* If you have tasks using `docker-worker`'s `dind`, `privileged` or `loopback-audio`
+  features, they are no longer supported. Either avoid using these features or migrate
+  to a `generic-worker` pool with D2G payloads enabled.
+* Ensure any task's using the `run-task` or `decision` images work with the new
+  Debian 13 base.
+
 19.x -> 20.x
 ------------
 
diff --git a/pyproject.toml b/pyproject.toml
index 876590c1b..e833a06bf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 ### Project
 [project]
 name = "taskcluster-taskgraph"
-version = "20.0.0"
+version = "21.0.0"
 description = "Build taskcluster taskgraphs"
 readme = "README.rst"
 authors = [
diff --git a/uv.lock b/uv.lock
index a68ac7d51..bb6c816fb 100644
--- a/uv.lock
+++ b/uv.lock
@@ -2587,7 +2587,7 @@ wheels = [
 
 [[package]]
 name = "taskcluster-taskgraph"
-version = "20.0.0"
+version = "21.0.0"
 source = { editable = "." }
 dependencies = [
     { name = "appdirs" },