- Symptom
- Source maps appear in Workers after upgrading Wrangler without config changesStack traces now show original file names and lines
- Cause
- From Wrangler 4.150.0, wrangler deploy, versions upload and preview generate and upload source maps without upload_source_maps being set. cf deploy and Vite plugin 1.64.0 or later do the same. Unresolvable maps such as inline data: maps are skipped silently unless upload_source_maps is true.
- Fix
- Set upload_source_maps to false to opt out, or true to make unresolvable maps fail the upload. For cf or the Vite plugin, set build.sourcemap to false.
- Apply
upload_source_maps = false- Affected
- Wrangler 4.150.0 and later, cf deploy, Cloudflare Vite plugin 1.64.0 and later, from 2026-10-20
- Sources
Last verified 2026-10-24 · Confirmed by 0 builders