# Vitest v4.0.16 — Release & Upgrade Intelligence
- **Product:** Vitest (https://vitest.dev)
- **Version:** v4.0.16
- **Released:** Dec 16, 2025
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/vitest/updates/v4.0.16/

## Executive Summary (TL;DR)
Vitest v4.0.16. Source highlight:    🐞 Bug Fixes

## Bug Fixes
- Fix browser mode default testTimeout back to 15 seconds &nbsp;-&nbsp; by @hi-ogawa in https://github.com/vitest-dev/vitest/issues/9167 <samp>(da0ad)</samp>
- Avoid crashing on `process.versions` stub &nbsp;-&nbsp; by @AriPerkkio in https://github.com/vitest-dev/vitest/issues/9174 <samp>(78cfb)</samp>
- Reject calling suite function inside test &nbsp;-&nbsp; by @hi-ogawa in https://github.com/vitest-dev/vitest/issues/9198 <samp>(1a259)</samp>
- Allow inlining fully dynamic import &nbsp;-&nbsp; by @hi-ogawa in https://github.com/vitest-dev/vitest/issues/9137 <samp>(56851)</samp>
- Fix module graph UI on html reporter with headless browser mode &nbsp;-&nbsp; by @hi-ogawa in https://github.com/vitest-dev/vitest/issues/9219 <samp>(60642)</samp>
- Log deprecated `test.poolOptions` if it's set &nbsp;-&nbsp; by @sheremet-va in https://github.com/vitest-dev/vitest/issues/9226 <samp>(f7f6a)</samp>