diff --git a/prompts/coder.md b/prompts/coder.md
index 840ccb4..2109890 100644
--- a/prompts/coder.md
+++ b/prompts/coder.md
@@ -17,5 +17,6 @@ Given a task description, you MUST:
 - Handle edge cases
 - Do NOT add unnecessary changes beyond what was requested
 - If creating a new file, include proper docstring/header
-- Respond in the same language as the existing code comments
+- 코드 주석(comment)과 문서(docstring, README 등)는 반드시 **한국어**로 작성하세요
+- 변수명, 함수명 등 코드 식별자는 영어 유지
 - After completion, briefly list what you changed