diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8b770f90fa..217ffd8326 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## Unreleased
+## 2025.9.0
 
 ### General
 -
diff --git a/package.json b/package.json
index 328397e710..df1b3892bb 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "misskey",
-	"version": "2025.8.0",
+	"version": "2025.9.0-alpha.0",
 	"codename": "nasubi",
 	"repository": {
 		"type": "git",
diff --git a/packages/misskey-js/package.json b/packages/misskey-js/package.json
index be26cb6b9d..e3122622c6 100644
--- a/packages/misskey-js/package.json
+++ b/packages/misskey-js/package.json
@@ -1,7 +1,7 @@
 {
 	"type": "module",
 	"name": "misskey-js",
-	"version": "2025.8.0",
+	"version": "2025.9.0-alpha.0",
 	"description": "Misskey SDK for JavaScript",
 	"license": "MIT",
 	"main": "./built/index.js",