Linear Haskell will be a part of GHC 8.12. This project has been going on for 4 years and involved a large amount of changes to GHC. In this talk, I will present an overview of changes - typechecker, Core, changes to optimization passes, extra argument to FunTy, interactions with parts of GHC that we did not expect. I will be paying particular attention to the changes in the simplifier that have been necessary to convey linearity information to Core Lint.