diff --git a/CHANGELOG.md b/CHANGELOG.md
index ebc450b1a1..feda6ebffd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## Unreleased
+## 2026.1.0
 
 ### Note
 - `users/following` の `birthday` プロパティは非推奨になりました。代わりに `users/get-following-birthday-users` をご利用ください。
diff --git a/package.json b/package.json
index 7254635950..76566042da 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "misskey",
-	"version": "2025.12.2",
+	"version": "2026.1.0-alpha.0",
 	"codename": "nasubi",
 	"repository": {
 		"type": "git",
diff --git a/packages/misskey-js/package.json b/packages/misskey-js/package.json
index f50d57b94a..0d1211001c 100644
--- a/packages/misskey-js/package.json
+++ b/packages/misskey-js/package.json
@@ -1,7 +1,7 @@
 {
 	"type": "module",
 	"name": "misskey-js",
-	"version": "2025.12.2",
+	"version": "2026.1.0-alpha.0",
 	"description": "Misskey SDK for JavaScript",
 	"license": "MIT",
 	"main": "./built/index.js",