[BUG] "Update available" banner shows when already on the latest version

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?

Claude Code displays an "Update available! Run: brew upgrade claude-code" banner on startup, even when the latest version is already installed.

What Should Happen?

The "Update available" banner should not appear when the installed version matches the latest release.

Error Messages/Logs

Update available! Run: brew upgrade claude-code

$ brew upgrade claude-code
Warning: Not upgrading claude-code, the latest version is already installed

Steps to Reproduce

1. Install Claude Code via Homebrew (version 2.1.81 — the latest)
2. Launch Claude Code
3. Observe the "Update available! Run: brew upgrade claude-code" banner
4. Run brew upgrade claude-code — confirms already on latest
5. Run claude --version → 2.1.81
6. Run brew info claude-code → claude-code: 2.1.81 (installed)

Claude Model

• Opus

Is this a regression?

I don't know

Claude Code Version

2.1.81 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Cosmetic issue only — no functional impact. Installed via Homebrew cask on macOS Darwin 25.3.0.