Tailwind config cannot import local TS modules in Next.js 16.1.x

[zoltroa]

Link to the code that reproduces this issue

https://codesandbox.io/p/devbox/tailwind-config-cannot-import-local-ts-modules-in-next-js-16-1-x-forked-tng34x

To Reproduce

• Start app in dev mode (next dev)
• Open console to check bug

Current vs. Expected behavior

Actual behavior:

• Error is reported as Module not found
• Project still runs

Expected behavior:

Not error

Provide environment information

Operating System:
  Platform: win32
  Arch: x64
  Version: Windows 10 Pro
  Available memory (MB): 16192
  Available CPU cores: 20
Binaries:
  Node: 24.12.0
  npm: 11.6.2
  Yarn: 1.22.22
  pnpm: N/A
Relevant Packages:
  next: 16.1.1 // Latest available version is detected (16.1.1).
  eslint-config-next: N/A
  react: 19.2.3
  react-dom: 19.2.3
  typescript: 5.9.3

Which area(s) are affected? (Select all that apply)

Turbopack

Which stage(s) are affected? (Select all that apply)

next dev (local), next build (local)

Additional context

After upgrading from Next.js 16.0.10 to 16.1.x, tailwind.config.ts can no longer import local TypeScript modules, even when using explicit relative paths.
The same configuration works correctly in 16.0.10.

[DRoet]

duplicate of #87898

[mischnic]

duplicate of #87898