diff --git a/CHANGELOG.md b/CHANGELOG.md
index e2feb57..307c982 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- fix release script to bump version number in flake.nix
+
 ## [v3.9.0] - 2024-03-09
 
 - add github-release-notifier formatter
diff --git a/docs/release.sh b/docs/release.sh
index 8a0d610..eaf4526 100755
--- a/docs/release.sh
+++ b/docs/release.sh
@@ -16,7 +16,7 @@ sed -i "/^\[Unreleased\]/s/$OLD/$NEW/" CHANGELOG.md
 sed -i "/^\[Unreleased\]/a [v$NEW]: https://github.com/nim65s/matrix-webhook/compare/v$OLD...v$NEW" CHANGELOG.md
 sed -i "/version/s/$OLD/$NEW/" flake.nix
 
-git add pyproject.toml CHANGELOG.md
+git add pyproject.toml CHANGELOG.md flake.nix
 git commit -m "Release v$NEW"
 git tag -s "v$NEW" -m "Release v$NEW"
 git push
diff --git a/flake.nix b/flake.nix
index d0b7644..0da9df4 100644
--- a/flake.nix
+++ b/flake.nix
@@ -20,7 +20,7 @@
           with pkgs.python3Packages;
           buildPythonApplication {
             pname = "matrix-webhook";
-            version = "3.8.0";
+            version = "3.9.0";
             src = pkgs.nix-gitignore.gitignoreSource [ ./.nixignore ] ./.;
             pyproject = true;
             buildInputs = [ poetry-core ];