ah - FWIW, you can still get much of the dev ergonomics without enabling PnP ( https://yarnpkg.com/getting-started/migration#step-by-step ), that part isn't required to upgrade (although you could still run into other migration issues like realizing some libraries have dependencies that are ambiguous about what version they want, and you'll have to specify them rather than letting the legacy resolver pick something unpredictably)