diff --git a/.github/workflows/release-artifacts.yml b/.github/workflows/release-artifacts.yml
index 41a7cb5611..8be377bded 100644
--- a/.github/workflows/release-artifacts.yml
+++ b/.github/workflows/release-artifacts.yml
@@ -50,6 +50,12 @@ jobs:
     name: "Build .deb packages"
     runs-on: ubuntu-latest
     strategy:
+      # Prevent all Debian package builds from being cancelled
+      # when one of them fails. Especially helpful when things are
+      # flaky during a release.
+      #
+      # `fail-fast` defaults to true and applies to the entire test matrix
+      fail-fast: false
       matrix:
         distro: ${{ fromJson(needs.get-distros.outputs.distros) }}
 
diff --git a/CHANGES.md b/CHANGES.md
index 13e25709cd..70a9b60e4f 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,14 @@
+# Synapse 1.155.0 (2026-06-16)
+
+## End of Life of Debian 12 Bookworm
+
+The next version of Synapse will not include Debian packages for Debian 12 Bookworm
+as it reached end of life on the 10th of June 2026.
+
+## Internal Changes
+
+- When building releases, don't cancel Debian package builds when one of them fails. ([\#19842](https://github.com/element-hq/synapse/issues/19842))
+
 # Synapse 1.155.0rc1 (2026-06-09)
 
 ## Bugfixes
diff --git a/debian/changelog b/debian/changelog
index 617bc73611..609b22438a 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.155.0) stable; urgency=medium
+
+  * New Synapse release 1.155.0.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 16 Jun 2026 14:44:04 +0100
+
 matrix-synapse-py3 (1.155.0~rc1) stable; urgency=medium
 
   * New Synapse release 1.155.0rc1.
diff --git a/pyproject.toml b/pyproject.toml
index 3500b4f516..fa70791f7a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "matrix-synapse"
-version = "1.155.0rc1"
+version = "1.155.0"
 description = "Homeserver for the Matrix decentralised comms protocol"
 readme = "README.rst"
 authors = [