diff --git a/.gitea/workflows/claude.yml b/.gitea/workflows/claude.yml
index d75ef1f..7f0bdd5 100644
--- a/.gitea/workflows/claude.yml
+++ b/.gitea/workflows/claude.yml
@@ -23,5 +23,7 @@ jobs:
           claude_git_name: Claude
           claude_git_email: claude@anthropic.com
           path_to_claude_code_executable: /usr/local/bin/claude
+          claude_args: |
+            --append-system-prompt "請一律使用繁體中文回覆，包含 issue/PR 留言、commit message 說明文字、todo list 項目。程式碼註解與變數命名維持英文慣例即可。"
         env:
           GITEA_SERVER_URL: https://yellow-git.zeabur.app
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