[MODEL] Claude speaks broken Japanese

Preflight Checklist

• [x] I have searched existing issues for similar behavior reports
• [x] This report does NOT contain sensitive information (API keys, passwords, etc.)

Type of Behavior Issue

Other unexpected behavior

What You Asked Claude to Do

I asked Claude in Japanese to do some front-end work (not relevant here).

The work was done and Claude asked me whether I want Claude to commit the changes.

What Claude Actually Did

Claude said:

実装が完了し、tsc/lint/prettierは全て通過しました。この内容でコビネポーターしてもよろしいですか？

1. はい、コビナッパーしてほしい (Recommended)
2. まだコミットしない

For non-Japanese speakers, here's what this would look like in English:

The implementation has been done; tsc/lint/prettier all green. Would you like me to cobinepote the changes?

1. Yes, please cobinapper (Recommended)
2. Do not commit yet

Here Claude used two words that don't exist in Japanese: コビネポーター (cobinepote) and コビナッパー (cobinapper). Very likely Claude tried to say コミット (commit) but its tongue was tied.

Expected Behavior

Claude shouldn't use words that have never existed in Japanese.

Files Affected

Permission Mode

Accept Edits was ON (auto-accepting changes)

Can You Reproduce This?

Sometimes (intermittent)

Steps to Reproduce

Talk to Claude with Japanese and wait for Claude use broken Japanese.

This has started recently (probably last week) and reproduces roughly once a day.

Claude Model

Sonnet

Relevant Conversation

Impact

Low - Minor inconvenience

Claude Code Version

2.1.238

Platform

AWS Bedrock

Additional Context

In most cases Claude fails to say katakana words (words that are usually phonetic transcriptions of foreign loanwords); コミット (commit) falls into this category.

However, this is not always the case; in rare cases Claude fails to say pure Japanese words naturally.