### Preflight Checklist - [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) and this hasn't been reported yet - [x] This is a single bug report (please file separate reports for different bugs) - [x] I am using the latest version of Claude Code ### What's Wrong? When I try to use Claude Opus 5 in Claude Desktop (Claude Code or Claude Cowork) to solve any biological tasks, the unexpected [bio] safeguard is triggere

[BUG] Unexpected biology safeguards in Claude Opus 5

Status Closed — not planned

Reported on v2.1.206

Maintainer reply None cached

Activity 1 comment · opened Sep 11, 2026 · closed Sep 18, 2026

Preflight Checklist

[x] I have searched existing issues and this hasn't been reported yet
[x] This is a single bug report (please file separate reports for different bugs)
[x] I am using the latest version of Claude Code

What's Wrong?

When I try to use Claude Opus 5 in Claude Desktop (Claude Code or Claude Cowork) to solve any biological tasks, the unexpected [bio] safeguard is triggered. According to https://www.anthropic.com/news/claude-opus-5 it should not act like this.

What Should Happen?

Opus 5 should not trigger safeguards at every biology-related task or question.

Error Messages/Logs

Steps to Reproduce

Ask

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.206

Platform

Other

Operating System

macOS

Terminal/Shell

Warp

Additional Information