diff -Naur b/boot/ghc-prim/ghc-prim.cabal a/boot/ghc-prim/ghc-prim.cabal
--- b/boot/ghc-prim/ghc-prim.cabal	2016-01-30 19:23:46.795893301 +0000
+++ a/boot/ghc-prim/ghc-prim.cabal	2016-01-30 19:23:44.727893337 +0000
@@ -23,17 +23,19 @@
 
 Library
     default-language: Haskell2010
+    default-extensions:
+        MagicHash
+        UnboxedTuples
+        NoImplicitPrelude
     other-extensions:
         BangPatterns
         CPP
         DeriveGeneric
         MagicHash
         MultiParamTypeClasses
-        NoImplicitPrelude
         StandaloneDeriving
         Trustworthy
         TypeFamilies
-        UnboxedTuples
         UnliftedFFITypes
 
     build-depends: rts == 1.0.*
diff -Naur b/boot/ghc-prim/Setup.hs a/boot/ghc-prim/Setup.hs
--- b/boot/ghc-prim/Setup.hs	2016-01-30 19:23:46.795893301 +0000
+++ a/boot/ghc-prim/Setup.hs	2016-01-30 19:23:44.731893337 +0000
@@ -1,2 +1,120 @@
+
+-- We need to do some ugly hacks here because of GHC magic
+
+module Main (main) where
+
+import Control.Monad
+import Data.List
+import Data.Maybe
+import Distribution.ModuleName (components)
+import Distribution.PackageDescription
 import Distribution.Simple
-main = defaultMain
+import Distribution.Simple.LocalBuildInfo
+import Distribution.Simple.Program
+import Distribution.Simple.Utils
+import Distribution.Simple.Setup
+import Distribution.Simple.Register
+import Distribution.Simple.Install
+import Distribution.Text
+import System.Cmd
+import System.FilePath
+import System.Exit
+import System.Directory
+
+import qualified Data.ByteString               as B
+import qualified Distribution.Compat.Exception as E
+
+main :: IO ()
+main = do let hooks = simpleUserHooks {
+                  regHook = addPrimModule
+                          $ regHook simpleUserHooks,
+                  instHook = myInstHook,
+                  buildHook = build_primitive_sources
+                            $ buildHook simpleUserHooks,
+                  haddockHook = addPrimModuleForHaddock
+                              $ build_primitive_sources
+                              $ haddockHook simpleUserHooks }
+          defaultMainWithHooks hooks
+
+type Hook a = PackageDescription -> LocalBuildInfo -> UserHooks -> a -> IO ()
+
+addPrimModule :: Hook a -> Hook a
+addPrimModule f pd lbi uhs x =
+    do let -- I'm not sure which one of these we actually need to change.
+           -- It seems bad that there are two.
+           pd' = addPrimModuleToPD pd
+           lpd = addPrimModuleToPD (localPkgDescr lbi)
+           lbi' = lbi { localPkgDescr = lpd }
+       f pd' lbi' uhs x
+
+addPrimModuleForHaddock :: Hook a -> Hook a
+addPrimModuleForHaddock f pd lbi uhs x =
+    do let pc = withPrograms lbi
+           pc' = userSpecifyArgs "haddock" ["GHC/Prim.hs"] pc
+           lbi' = lbi { withPrograms = pc' }
+       f pd lbi' uhs x
+
+addPrimModuleToPD :: PackageDescription -> PackageDescription
+addPrimModuleToPD pd =
+    case library pd of
+    Just lib ->
+        let ems = fromJust (simpleParse "GHC.Prim") : exposedModules lib
+            lib' = lib { exposedModules = ems }
+        in pd { library = Just lib' }
+    Nothing ->
+        error "Expected a library, but none found"
+
+build_primitive_sources :: Hook a -> Hook a
+build_primitive_sources f pd lbi uhs x
+ = do when (compilerFlavor (compiler lbi) == GHC ||
+            compilerFlavor (compiler lbi) == GHCJS) $ do
+          let genprimopcode = joinPath ["..", "..", "utils",
+                                        "genprimopcode", "genprimopcode"]
+              runGenprimopcode options tmp out = do
+                writeFile tmp "{-# LANGUAGE CPP #-}\n#ifdef ghcjs_HOST_OS\n"
+                maybeExit $ system (genprimopcode ++ options ++ " < " ++ primops ++ " >> " ++ tmp)
+                appendFile tmp "\n#else\n"
+                maybeExit $ system (genprimopcode ++ options ++ " < " ++ primops_native ++ " >> " ++ tmp)
+                appendFile tmp "\n#endif\n"
+                maybeUpdateFile tmp out
+              primops = joinPath ["..", "..", "data", "primops-js.txt"]
+              primops_native = joinPath ["..", "..", "data", "primops-native.txt"]
+              primhs = joinPath ["GHC", "Prim.hs"]
+              primopwrappers = joinPath ["GHC", "PrimopWrappers.hs"]
+              primhs_tmp = addExtension primhs "tmp"
+              primopwrappers_tmp = addExtension primopwrappers "tmp"
+          runGenprimopcode " --make-haskell-source"   primhs_tmp primhs
+          runGenprimopcode " --make-haskell-wrappers" primopwrappers_tmp primopwrappers
+      f pd lbi uhs x
+
+-- Replace a file only if the new version is different from the old.
+-- This prevents make from doing unnecessary work after we run 'setup makefile'
+maybeUpdateFile :: FilePath -> FilePath -> IO ()
+maybeUpdateFile source target = do
+  let readf file = fmap (either (const Nothing) Just) (E.tryIO $ B.readFile file)
+  s <- readf source
+  t <- readf  target
+  if isJust s && s == t
+    then removeFile source
+    else do doesFileExist target >>= flip when (removeFile target)
+            renameFile source target
+
+myInstHook :: PackageDescription -> LocalBuildInfo
+                   -> UserHooks -> InstallFlags -> IO ()
+myInstHook pkg_descr localbuildinfo uh flags = do
+  let copyFlags = defaultCopyFlags {
+                      copyDistPref   = installDistPref flags,
+                      copyDest       = toFlag NoCopyDest,
+                      copyVerbosity  = installVerbosity flags
+                  }
+  install pkg_descr localbuildinfo copyFlags
+  let registerFlags = defaultRegisterFlags {
+                          regDistPref  = installDistPref flags,
+                          regInPlace   = installInPlace flags,
+                          regPackageDB = installPackageDB flags,
+                          regVerbosity = installVerbosity flags
+                      }
+  when (hasLibs pkg_descr) $ addPrimModule (\pd lbi _ -> register pd lbi)
+     pkg_descr localbuildinfo uh registerFlags
+
+
diff -Naur b/boot/ghc-prim/tests/T6026.hs a/boot/ghc-prim/tests/T6026.hs
--- b/boot/ghc-prim/tests/T6026.hs	1970-01-01 01:00:00.000000000 +0100
+++ a/boot/ghc-prim/tests/T6026.hs	2016-01-30 19:23:44.731893337 +0000
@@ -0,0 +1,10 @@
+{-# LANGUAGE MagicHash #-}
+
+module Main (main) where
+
+import GHC.Prim
+import GHC.Types
+
+main :: IO ()
+main = print (I# (1# +# 2# *# 3# +# 4#))
+
diff -Naur b/boot/ghc-prim/tests/T6026.stdout a/boot/ghc-prim/tests/T6026.stdout
--- b/boot/ghc-prim/tests/T6026.stdout	1970-01-01 01:00:00.000000000 +0100
+++ a/boot/ghc-prim/tests/T6026.stdout	2016-01-30 19:23:44.731893337 +0000
@@ -0,0 +1 @@
+11