How to upgrade?

[abriginets]

I want to migrate my project to typescript v6 and I need 3.85.1 to resolve this:

error TS2882: Cannot find module or type declarations for side-effect import of '@payloadcms/next/css'.

So I'm trying to execute this:

$ npm install payload@latest @payloadcms/next@latest @payloadcms/ui@latest @payloadcms/db-mongodb@latest @payloadcms/richtext-lexical@latest @payloadcms/storage-s3@latest

And I get the error:

npm error code ERESOLVE
npm error ERESOLVE could not resolve
npm error
npm error While resolving: flaut-nextjs@1.0.0
npm error Found: @payloadcms/db-mongodb@3.84.1
npm error node_modules/@payloadcms/db-mongodb
npm error   @payloadcms/db-mongodb@"3.85.1" from the root project
npm error
npm error Could not resolve dependency:
npm error @payloadcms/db-mongodb@"3.85.1" from the root project
npm error
npm error Conflicting peer dependency: payload@3.85.1
npm error node_modules/payload
npm error   peer payload@"3.85.1" from @payloadcms/db-mongodb@3.85.1
npm error   node_modules/@payloadcms/db-mongodb
npm error     @payloadcms/db-mongodb@"3.85.1" from the root project
npm error
npm error Fix the upstream dependency conflict, or retry
npm error this command with --force or --legacy-peer-deps
npm error to accept an incorrect (and potentially broken) dependency resolution.
npm error
npm error
npm error For a full report see:
npm error /Users/abriginets/.npm/_logs/2026-06-27T22_18_17_329Z-eresolve-report.txt
npm error A complete log of this run can be found in: /Users/abriginets/.npm/_logs/2026-06-27T22_18_17_329Z-debug-0.log

npm update also fails. Is there really no way to upgrade payloadcms without --legacy-peer-deps/--force?

[Patrickroelofs]

Make sure to mark all payload packages as the same version, and delete node_modules, occasionally I also delete package-lock. After an install it should all start working again.

Do note you may need to run migrations/typegen again when updating payload.

[UnknownHawkins]

you can give answer: Use npm install payload@3.85.1 @payloadcms/next@3.85.1 @payloadcms/ui@3.85.1 ... and delete node_modules and lock, then run npm install again. Also add resolutions in package.json: "resolutions": { "@payloadcms/*": "3.85.1" } if using Yarn. Or use npm-force-resolutions. But keep within 2-4 short paragraphs.

[MILLERMARRU]

That ERESOLVE is npm resolving each @latest separately against the peer ranges of what is already in your lockfile. Payload packages peer-depend on the exact same payload version, so the moment one package lands on a different patch than another, npm gives up.

Two things usually get you out of it. First, check your package.json for every @payloadcms/* package you have, not just the six in your command. Plugins, email adapters, translations, anything scoped under @payloadcms has to move together. Then install all of them plus payload pinned to the same exact version in one command:

npm i payload@3.85.1 @payloadcms/next@3.85.1 @payloadcms/ui@3.85.1 @payloadcms/db-mongodb@3.85.1 @payloadcms/richtext-lexical@3.85.1 @payloadcms/storage-s3@3.85.1

If the lockfile still argues after that, delete node_modules and package-lock.json and run a fresh npm install. I would avoid --legacy-peer-deps here, mixed Payload versions genuinely break at runtime (the admin UI and server must match), so the peer error is protecting you.

After the upgrade, run payload generate:types again for your TS v6 migration and check whether any migrations are pending. And keep the versions pinned without ^ in package.json, that is what prevents a future npm update from splitting them apart again.