diff --git a/CHANGES.md b/CHANGES.md
index 91fe74c60f..4a7db445c2 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,12 @@
+# Synapse 1.138.1 (2025-09-24)
+
+## Bugfixes
+
+- Fix a performance regression related to the experimental Delayed Events ([MSC4140](https://github.com/matrix-org/matrix-spec-proposals/pull/4140)) feature. ([\#18926](https://github.com/element-hq/synapse/issues/18926))
+
+
+
+
 # Synapse 1.138.0 (2025-09-09)
 
 No significant changes since 1.138.0rc1.
diff --git a/changelog.d/18926.bugfix b/changelog.d/18926.bugfix
deleted file mode 100644
index c450313764..0000000000
--- a/changelog.d/18926.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a performance regression related to the experimental Delayed Events ([MSC4140](https://github.com/matrix-org/matrix-spec-proposals/pull/4140)) feature.
\ No newline at end of file
diff --git a/debian/changelog b/debian/changelog
index 035d06ad2b..f5403f7b6b 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.138.1) stable; urgency=medium
+
+  * New Synapse release 1.138.1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Wed, 24 Sep 2025 11:32:38 +0100
+
 matrix-synapse-py3 (1.138.0) stable; urgency=medium
 
   * New Synapse release 1.138.0.
diff --git a/pyproject.toml b/pyproject.toml
index f9dd0ca26b..7b756bc614 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -101,7 +101,7 @@ module-name = "synapse.synapse_rust"
 
 [tool.poetry]
 name = "matrix-synapse"
-version = "1.138.0"
+version = "1.138.1"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
 license = "AGPL-3.0-or-later"