diff --git a/CHANGELOG.md b/CHANGELOG.md
index 90ad015da..cbd48b8b6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@
   - どのアカウントで認証しようとしているのかがわかるように
   - 認証するアカウントを切り替えられるように
 - Enhance: Self-XSS防止用の警告を追加
+- Enhance: カタルーニャ語 (ca-ES) に対応  
 - Fix: 通知の範囲指定の設定項目が必要ない通知設定でも範囲指定の設定がでている問題を修正
 - Fix: Turnstileが失敗・期限切れした際にも成功扱いとなってしまう問題を修正  
   (Cherry-picked from https://github.com/MisskeyIO/misskey/pull/768)
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 3bc0faf96..4bcf7e164 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -132,7 +132,8 @@ You can improve our translations with your Crowdin account.
 Your changes in Crowdin are automatically submitted as a PR (with the title "New Crowdin translations") to the repository.
 The owner [@syuilo](https://github.com/syuilo) merges the PR into the develop branch before the next release.
 
-If your language is not listed in Crowdin, please open an issue.
+If your language is not listed in Crowdin, please open an issue. We will add it to Crowdin.
+For newly added languages, once the translation progress per language exceeds 70%, it will be officially introduced into Misskey and made available to users.
 
 ![Crowdin](https://d322cqt584bo4o.cloudfront.net/misskey/localized.svg)
 
diff --git a/locales/index.js b/locales/index.js
index c2738884e..091d216de 100644
--- a/locales/index.js
+++ b/locales/index.js
@@ -15,6 +15,7 @@ const merge = (...args) => args.reduce((a, c) => ({
 
 const languages = [
 	'ar-SA',
+	'ca-ES',
 	'cs-CZ',
 	'da-DK',
 	'de-DE',