diff --git a/.github/workflows/release-artifacts.yml b/.github/workflows/release-artifacts.yml
index 5b5bfc1896..10583bc060 100644
--- a/.github/workflows/release-artifacts.yml
+++ b/.github/workflows/release-artifacts.yml
@@ -221,3 +221,7 @@ jobs:
             Sdist/*
             Wheel*/*
             debs.tar.xz
+          # if it's not already published, keep the release as a draft.
+          draft: true
+          # mark it as a prerelease if the tag contains 'rc'.
+          prerelease: ${{ contains(github.ref, 'rc') }}
diff --git a/CHANGES.md b/CHANGES.md
index 20177bf00a..6096463cc6 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,12 @@
+# Synapse 1.121.0 (2024-12-11)
+
+### Internal Changes
+
+- Fix release process to not create duplicate releases. ([\#18025](https://github.com/element-hq/synapse/issues/18025))
+
+
+
+
 # Synapse 1.121.0rc1 (2024-12-04)
 
 This release candidate contains the security fixes from [v1.120.2](https://github.com/element-hq/synapse/releases/tag/v1.120.2).
diff --git a/debian/changelog b/debian/changelog
index 805c036c82..8149cd7486 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.121.0) stable; urgency=medium
+
+  * New Synapse release 1.121.0.
+
+ -- Synapse Packaging team <packages@matrix.org>  Wed, 11 Dec 2024 13:12:30 +0100
+
 matrix-synapse-py3 (1.121.0~rc1) stable; urgency=medium
 
   * New Synapse release 1.121.0rc1.
diff --git a/pyproject.toml b/pyproject.toml
index e5051770f5..a8a86b4d5c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -97,7 +97,7 @@ module-name = "synapse.synapse_rust"
 
 [tool.poetry]
 name = "matrix-synapse"
-version = "1.121.0rc1"
+version = "1.121.0"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
 license = "AGPL-3.0-or-later"