It appears `language-javascript` follows the PVP. Version `0.7.1.0` was recently released, which bumps from `0.7.0.0`. However, `0.7.1.0` includes https://github.com/erikd/language-javascript/pull/113, which adds new data constructors to an exported data type. I asked about this on the Haskell discourse, and it appears there is a (small amount of) consensus that adding a new data constructor requires a major version bump: https://discourse.haskell.org/t/does-adding-a-data-constructor-require-a-major-version-bump-according-to-the-pvp/3600/3 So `0.7.1.0` should have been `0.8.0.0`.