diff --git a/CHANGELOG.md b/CHANGELOG.md
index e841ea2791..8549d7cb87 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## Unreleased
+## 2025.9.1
 
 ### General
 - Enhance: 広告ごとにセンシティブフラグを設定できるようになりました
diff --git a/package.json b/package.json
index 7f19734453..b8d038dc21 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "misskey",
-	"version": "2025.9.0",
+	"version": "2025.9.1-alpha.0",
 	"codename": "nasubi",
 	"repository": {
 		"type": "git",
diff --git a/packages/misskey-js/package.json b/packages/misskey-js/package.json
index ac93ad9f7d..d5f2c34229 100644
--- a/packages/misskey-js/package.json
+++ b/packages/misskey-js/package.json
@@ -1,7 +1,7 @@
 {
 	"type": "module",
 	"name": "misskey-js",
-	"version": "2025.9.0",
+	"version": "2025.9.1-alpha.0",
 	"description": "Misskey SDK for JavaScript",
 	"license": "MIT",
 	"main": "./built/index.js",