diff --git a/ChangeLog.md b/ChangeLog.md
index 8860e0f..50ecb5c 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -4,6 +4,7 @@
 # 0.4.7.0
 - Support GHC 9.12.
 - Support GHC 9.14.
+- Remove support for GHC < 9.0.
 
 # 0.4.6.0
 - Support GHC 9.10.
diff --git a/compat-8.10/GHC/Driver/Monad.hs b/compat-8.10/GHC/Driver/Monad.hs
deleted file mode 100644
index 400e560..0000000
--- a/compat-8.10/GHC/Driver/Monad.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Driver.Monad (module GhcMonad) where
-import GhcMonad
diff --git a/compat-8.10/GHC/Driver/Session.hs b/compat-8.10/GHC/Driver/Session.hs
deleted file mode 100644
index 41916b7..0000000
--- a/compat-8.10/GHC/Driver/Session.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Driver.Session (module DynFlags) where
-import DynFlags
diff --git a/compat-8.10/GHC/Hs/Type.hs b/compat-8.10/GHC/Hs/Type.hs
deleted file mode 100644
index ea69831..0000000
--- a/compat-8.10/GHC/Hs/Type.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.Type (module GHC.Hs.Types) where
-import GHC.Hs.Types
\ No newline at end of file
diff --git a/compat-8.10/GHC/Plugins.hs b/compat-8.10/GHC/Plugins.hs
deleted file mode 100644
index 6f3444d..0000000
--- a/compat-8.10/GHC/Plugins.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Plugins (module GhcPlugins) where
-import GhcPlugins
\ No newline at end of file
diff --git a/compat-8.10/GHC/Tc/Types/Evidence.hs b/compat-8.10/GHC/Tc/Types/Evidence.hs
deleted file mode 100644
index e448c5c..0000000
--- a/compat-8.10/GHC/Tc/Types/Evidence.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Tc.Types.Evidence (module TcEvidence) where
-import TcEvidence
\ No newline at end of file
diff --git a/compat-8.10/GHC/Types/Basic.hs b/compat-8.10/GHC/Types/Basic.hs
deleted file mode 100644
index eec2bb6..0000000
--- a/compat-8.10/GHC/Types/Basic.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Types.Basic (module BasicTypes) where
-import BasicTypes
\ No newline at end of file
diff --git a/compat-8.10/GHC/Utils/Outputable.hs b/compat-8.10/GHC/Utils/Outputable.hs
deleted file mode 100644
index 69bc10b..0000000
--- a/compat-8.10/GHC/Utils/Outputable.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Utils.Outputable (module Outputable) where
-import Outputable
diff --git a/compat/GHC/Driver/Monad.hs b/compat/GHC/Driver/Monad.hs
deleted file mode 100644
index 400e560..0000000
--- a/compat/GHC/Driver/Monad.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Driver.Monad (module GhcMonad) where
-import GhcMonad
diff --git a/compat/GHC/Driver/Session.hs b/compat/GHC/Driver/Session.hs
deleted file mode 100644
index 41916b7..0000000
--- a/compat/GHC/Driver/Session.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Driver.Session (module DynFlags) where
-import DynFlags
diff --git a/compat/GHC/Hs.hs b/compat/GHC/Hs.hs
deleted file mode 100644
index 9ec9e1c..0000000
--- a/compat/GHC/Hs.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs (module HsSyn) where
-import HsSyn
\ No newline at end of file
diff --git a/compat/GHC/Hs/Binds.hs b/compat/GHC/Hs/Binds.hs
deleted file mode 100644
index e52d6ae..0000000
--- a/compat/GHC/Hs/Binds.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.Binds (module HsBinds) where
-import HsBinds
diff --git a/compat/GHC/Hs/Decls.hs b/compat/GHC/Hs/Decls.hs
deleted file mode 100644
index c424527..0000000
--- a/compat/GHC/Hs/Decls.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.Decls (module HsDecls) where
-import HsDecls
diff --git a/compat/GHC/Hs/Expr.hs b/compat/GHC/Hs/Expr.hs
deleted file mode 100644
index 7bbd10c..0000000
--- a/compat/GHC/Hs/Expr.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.Expr (module HsExpr) where
-import HsExpr
diff --git a/compat/GHC/Hs/Extension.hs b/compat/GHC/Hs/Extension.hs
deleted file mode 100644
index 45dd589..0000000
--- a/compat/GHC/Hs/Extension.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.Extension (module HsExtension) where
-import HsExtension
diff --git a/compat/GHC/Hs/ImpExp.hs b/compat/GHC/Hs/ImpExp.hs
deleted file mode 100644
index bfd6ac2..0000000
--- a/compat/GHC/Hs/ImpExp.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.ImpExp (module HsImpExp) where
-import HsImpExp
diff --git a/compat/GHC/Hs/Lit.hs b/compat/GHC/Hs/Lit.hs
deleted file mode 100644
index ea39661..0000000
--- a/compat/GHC/Hs/Lit.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.Lit (module HsLit) where
-import HsLit
diff --git a/compat/GHC/Hs/Pat.hs b/compat/GHC/Hs/Pat.hs
deleted file mode 100644
index a8983e7..0000000
--- a/compat/GHC/Hs/Pat.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.Pat (module HsPat) where
-import HsPat
diff --git a/compat/GHC/Hs/Type.hs b/compat/GHC/Hs/Type.hs
deleted file mode 100644
index 7828be4..0000000
--- a/compat/GHC/Hs/Type.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.Type (module HsTypes) where
-import HsTypes
\ No newline at end of file
diff --git a/compat/GHC/Hs/Utils.hs b/compat/GHC/Hs/Utils.hs
deleted file mode 100644
index 9417f1b..0000000
--- a/compat/GHC/Hs/Utils.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Hs.Utils (module HsUtils) where
-import HsUtils
diff --git a/compat/GHC/Plugins.hs b/compat/GHC/Plugins.hs
deleted file mode 100644
index 6f3444d..0000000
--- a/compat/GHC/Plugins.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Plugins (module GhcPlugins) where
-import GhcPlugins
\ No newline at end of file
diff --git a/compat/GHC/Tc/Types/Evidence.hs b/compat/GHC/Tc/Types/Evidence.hs
deleted file mode 100644
index e448c5c..0000000
--- a/compat/GHC/Tc/Types/Evidence.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Tc.Types.Evidence (module TcEvidence) where
-import TcEvidence
\ No newline at end of file
diff --git a/compat/GHC/Types/Basic.hs b/compat/GHC/Types/Basic.hs
deleted file mode 100644
index eec2bb6..0000000
--- a/compat/GHC/Types/Basic.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Types.Basic (module BasicTypes) where
-import BasicTypes
\ No newline at end of file
diff --git a/compat/GHC/Utils/Outputable.hs b/compat/GHC/Utils/Outputable.hs
deleted file mode 100644
index 69bc10b..0000000
--- a/compat/GHC/Utils/Outputable.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-module GHC.Utils.Outputable (module Outputable) where
-import Outputable
diff --git a/ghc-show-ast/Main.hs b/ghc-show-ast/Main.hs
index 49a5dca..0e366e8 100644
--- a/ghc-show-ast/Main.hs
+++ b/ghc-show-ast/Main.hs
@@ -26,11 +26,10 @@ import qualified GHC.Types.Error as GHC (NoDiagnosticOpts(..))
 #elif MIN_VERSION_ghc(9,2,0)
 import qualified GHC.Driver.Errors as Error
 import qualified GHC.Parser.Errors.Ppr as Error
-#elif MIN_VERSION_ghc(9,0,0)
+#else
 import qualified GHC.Utils.Error as Error
 #endif
 
-#if MIN_VERSION_ghc(9,0,1)
 import GHC.Data.FastString
 import GHC.Types.Name
     ( Name
@@ -63,49 +62,8 @@ import qualified GHC.Types.SrcLoc as GHC
 import qualified GHC.Data.StringBuffer as GHC
 import GHC.Paths (libdir)
 import GHC.Driver.Monad (liftIO)
-#else
-import FastString
-import Name
-    ( Name
-    , isExternalName
-    , isInternalName
-    , isSystemName
-    , isWiredInName
-    , nameOccName
-    , nameUnique
-    )
-import OccName
-    ( OccName
-    , occNameSpace
-    , occNameString
-    , NameSpace
-    , varName
-    , dataName
-    , tvName
-    , tcClsName
-    )
-
-import qualified DynFlags as GHC
-import qualified FastString as GHC
-import qualified GHC as GHC
-import qualified GhcMonad as GHC
-import qualified HeaderInfo as GHC
-import qualified Lexer as GHC
-import qualified Parser as Parser
-import qualified SrcLoc as GHC
-import qualified StringBuffer as GHC
-import GHC.Paths (libdir)
-#if MIN_VERSION_ghc(8,10,0)
-import GhcMonad (liftIO)
-import qualified ErrUtils as Error
-#else
-import qualified Outputable as GHC
-#endif
-#endif
 
-#if MIN_VERSION_ghc(8,10,0)
 import System.Exit (exitFailure)
-#endif
 
 main :: IO ()
 main = do
@@ -113,7 +71,7 @@ main = do
     result <- parseModule f
     print $ gPrint result
 
-#if MIN_VERSION_ghc(9,0,1) && !MIN_VERSION_ghc(9,6,0)
+#if !MIN_VERSION_ghc(9,6,0)
 parseModule :: FilePath -> IO GHC.HsModule
 #else
 parseModule :: FilePath -> IO (GHC.HsModule GHC.GhcPs)
@@ -190,18 +148,11 @@ parseModule f = GHC.runGhc (Just libdir) $ do
                 let errors = Error.pprError <$> GHC.getErrorMessages s
                 Error.printBagOfErrors logger dflags errors
                 exitFailure
-#elif MIN_VERSION_ghc(8,10,0)
+#else
         GHC.PFailed s -> liftIO $ do
                 let (_warnings, errors) = GHC.messages s dflags
                 Error.printBagOfErrors dflags errors
                 exitFailure
-#else
-        GHC.PFailed
-            -- Note: using printBagOfErrors on the messages doesn't produce any
-            -- useful output on older GHCs; so instead print the docs directly.
-            _messages
-            loc docs ->
-            error $ GHC.showPpr dflags loc ++ ": " ++ GHC.showSDoc dflags docs
 #endif
 
 gPrint :: Data a => a -> Doc
diff --git a/ghc-source-gen.cabal b/ghc-source-gen.cabal
index 7a177b6..51219c1 100644
--- a/ghc-source-gen.cabal
+++ b/ghc-source-gen.cabal
@@ -60,34 +60,9 @@ library
       FlexibleInstances
       TypeSynonymInstances
   build-depends:
-      base >=4.7 && <5
-    , ghc >=8.4 && <9.15
+      base >=4.15 && <5
+    , ghc >=9.0 && <9.15
   default-language: Haskell2010
-  if impl(ghc<8.10)
-    other-modules:
-        GHC.Hs
-        GHC.Hs.Binds
-        GHC.Hs.Decls
-        GHC.Hs.Expr
-        GHC.Hs.Extension
-        GHC.Hs.ImpExp
-        GHC.Hs.Lit
-        GHC.Hs.Pat
-        GHC.Hs.Utils
-    hs-source-dirs:
-        compat
-  if impl(ghc<9.0)
-    other-modules:
-        GHC.Hs.Type
-        GHC.Driver.Monad
-        GHC.Driver.Session
-        GHC.Utils.Outputable
-        GHC.Types.Basic
-        GHC.Plugins
-        GHC.Tc.Types.Evidence
-  if impl(ghc>=8.10) && impl(ghc<9.0)
-    hs-source-dirs:
-        compat-8.10
 
 test-suite name_test
   type: exitcode-stdio-1.0
@@ -103,8 +78,8 @@ test-suite name_test
       TypeSynonymInstances
   build-depends:
       QuickCheck >=2.10 && <2.17
-    , base >=4.7 && <5
-    , ghc >=8.4 && <9.15
+    , base >=4.15 && <5
+    , ghc >=9.0 && <9.15
     , ghc-source-gen
     , tasty >=1.0 && <1.6
     , tasty-hunit ==0.10.*
@@ -124,18 +99,13 @@ test-suite pprint_examples
       FlexibleInstances
       TypeSynonymInstances
   build-depends:
-      base >=4.7 && <5
-    , ghc >=8.4 && <9.15
+      base >=4.15 && <5
+    , ghc >=9.0 && <9.15
     , ghc-paths ==0.1.*
     , ghc-source-gen
     , tasty >=1.0 && <1.6
     , tasty-hunit ==0.10.*
   default-language: Haskell2010
-  if impl(ghc<9.0)
-    other-modules:
-        GHC.Utils.Outputable
-    hs-source-dirs:
-        compat
 
 test-suite pprint_test
   type: exitcode-stdio-1.0
@@ -150,17 +120,10 @@ test-suite pprint_test
       FlexibleInstances
       TypeSynonymInstances
   build-depends:
-      base >=4.7 && <5
-    , ghc >=8.4 && <9.15
+      base >=4.15 && <5
+    , ghc >=9.0 && <9.15
     , ghc-paths ==0.1.*
     , ghc-source-gen
     , tasty >=1.0 && <1.6
     , tasty-hunit ==0.10.*
   default-language: Haskell2010
-  if impl(ghc<9.0)
-    other-modules:
-        GHC.Driver.Monad
-        GHC.Driver.Session
-        GHC.Utils.Outputable
-    hs-source-dirs:
-        compat
diff --git a/package.yaml b/package.yaml
index c6770a1..94f5c29 100644
--- a/package.yaml
+++ b/package.yaml
@@ -29,8 +29,8 @@ description: |
     For more information, please see the <https://github.com/google/ghc-source-gen README>.
 
 dependencies:
-- base >= 4.7 && < 5
-- ghc >= 8.4 && < 9.15
+- base >= 4.15 && < 5
+- ghc >= 9.0 && < 9.15
 
 default-extensions:
 - DataKinds
@@ -38,36 +38,6 @@ default-extensions:
 - TypeSynonymInstances
 
 library:
-  when:
-  # GHC-8.10 introduced hierarchical modules.
-  # For compatibility, define wrapper modules for older GHC versions.
-  - condition: impl(ghc<8.10)
-    source-dirs: compat
-    other-modules:
-    - GHC.Hs
-    - GHC.Hs.Binds
-    - GHC.Hs.Decls
-    - GHC.Hs.Expr
-    - GHC.Hs.Extension
-    - GHC.Hs.ImpExp
-    - GHC.Hs.Lit
-    - GHC.Hs.Pat
-    - GHC.Hs.Utils
-
-  verbatim: |
-    if impl(ghc<9.0)
-      other-modules:
-          GHC.Hs.Type
-          GHC.Driver.Monad
-          GHC.Driver.Session
-          GHC.Utils.Outputable
-          GHC.Types.Basic
-          GHC.Plugins
-          GHC.Tc.Types.Evidence
-    if impl(ghc>=8.10) && impl(ghc<9.0)
-      hs-source-dirs:
-          compat-8.10
-
   source-dirs: src
   other-modules:
   - GHC.SourceGen.Binds.Internal
@@ -87,12 +57,6 @@ tests:
     - tasty >= 1.0 && < 1.6
     - tasty-hunit == 0.10.*
 
-    when:
-    - condition: impl(ghc<9.0)
-      source-dirs: compat
-      other-modules:
-      - GHC.Utils.Outputable
-
   # TODO: Fill out this test, and use it to replace pprint_examples.
   pprint_test:
     main: pprint_test.hs
@@ -103,14 +67,6 @@ tests:
     - tasty >= 1.0 && < 1.6
     - tasty-hunit == 0.10.*
 
-    when:
-    - condition: impl(ghc<9.0)
-      source-dirs: compat
-      other-modules:
-      - GHC.Driver.Monad
-      - GHC.Driver.Session
-      - GHC.Utils.Outputable
-
   name_test:
     main: name_test.hs
     source-dirs: tests
diff --git a/src/GHC/SourceGen/Binds.hs b/src/GHC/SourceGen/Binds.hs
index 377c918..0bc9226 100644
--- a/src/GHC/SourceGen/Binds.hs
+++ b/src/GHC/SourceGen/Binds.hs
@@ -46,20 +46,13 @@ module GHC.SourceGen.Binds
     , (<--)
     ) where
 
-#if MIN_VERSION_ghc(9,0,0)
 import GHC (LexicalFixity(..))
-#else
-import GHC.Types.Basic (LexicalFixity(..))
-#endif
 import Data.Bool (bool)
 import Data.Maybe (fromMaybe)
 import GHC.Hs.Binds
 import GHC.Hs.Expr
 import GHC.Hs.Type
 import GHC.Plugins (isSymOcc)
-#if !MIN_VERSION_ghc(9,0,1)
-import GHC.Tc.Types.Evidence (HsWrapper(WpHole))
-#endif
 
 #if MIN_VERSION_ghc(9,10,0)
 import GHC.Parser.Annotation (noAnn)
@@ -117,9 +110,6 @@ funBindsWithFixity :: HasValBind t => Maybe LexicalFixity -> OccNameStr -> [RawM
 funBindsWithFixity fixity name matches = bindB $ withPlaceHolder
         (noExt FunBind name'
             (matchGroup context matches)
-#if !MIN_VERSION_ghc(9,0,1)
-            WpHole
-#endif
             )
 #if !MIN_VERSION_ghc(9,6,0)
         []
@@ -333,11 +323,8 @@ stmt e =
 (<--) :: Pat' -> HsExpr' -> Stmt'
 #if MIN_VERSION_ghc(9,10,0)
 p <-- e = withPlaceHolder $ BindStmt noAnn (builtPat p) (mkLocated e)
-#elif MIN_VERSION_ghc(9,0,0)
-p <-- e = withPlaceHolder $ withEpAnnNotUsed BindStmt (builtPat p) (mkLocated e)
 #else
 p <-- e = withPlaceHolder $ withEpAnnNotUsed BindStmt (builtPat p) (mkLocated e)
-         noSyntaxExpr noSyntaxExpr
 #endif
 infixl 1 <--
 
diff --git a/src/GHC/SourceGen/Binds/Internal.hs b/src/GHC/SourceGen/Binds/Internal.hs
index 33ae9d8..ff0a84e 100644
--- a/src/GHC/SourceGen/Binds/Internal.hs
+++ b/src/GHC/SourceGen/Binds/Internal.hs
@@ -8,7 +8,6 @@
 {-# LANGUAGE TypeApplications #-}
 module GHC.SourceGen.Binds.Internal where
 
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Types.Basic ( Origin(Generated)
 #if MIN_VERSION_ghc(9,10,0)
                        , GenReason(OtherExpansion)
@@ -19,10 +18,6 @@ import GHC.Types.Basic ( Origin(Generated)
                        )
 import GHC.Data.Bag (listToBag)
 import GHC.Hs.Extension (GhcPs)
-#else
-import BasicTypes (Origin(Generated))
-import Bag (listToBag)
-#endif
 import GHC.Hs.Binds
 import GHC.Hs.Decls
 import GHC.Hs.Expr (MatchGroup(..), Match(..), GRHSs(..))
@@ -34,10 +29,6 @@ import qualified Data.List.NonEmpty as NonEmpty
 import Language.Haskell.Syntax.Extension (wrapXRec, noExtField)
 #endif
 
-#if !MIN_VERSION_ghc(8,6,0)
-import PlaceHolder (PlaceHolder(..))
-#endif
-
 #if MIN_VERSION_ghc(9,10,0)
 import GHC.Parser.Annotation (noAnn, emptyComments)
 #endif
@@ -67,14 +58,9 @@ valBinds vbs =
             (listToBag $ map mkLocated binds)
 #  endif
             (map mkLocated sigs)
-#elif MIN_VERSION_ghc(8,6,0)
-    withEpAnnNotUsed HsValBinds
-        $ withNoAnnSortKey ValBinds
-            (listToBag $ map mkLocated binds)
-            (map mkLocated sigs)
 #else
     withEpAnnNotUsed HsValBinds
-        $ noExt ValBindsIn
+        $ withNoAnnSortKey ValBinds
             (listToBag $ map mkLocated binds)
             (map mkLocated sigs)
 #endif
@@ -125,9 +111,7 @@ matchGroup context matches =
     noExt MG
 #endif
                             matches'
-#if !MIN_VERSION_ghc(8,6,0)
-                            [] PlaceHolder
-#elif !MIN_VERSION_ghc(9,6,0)
+#if !MIN_VERSION_ghc(9,6,0)
                             Generated
 #endif
   where
diff --git a/src/GHC/SourceGen/Decl.hs b/src/GHC/SourceGen/Decl.hs
index 5856cfc..a725fc7 100644
--- a/src/GHC/SourceGen/Decl.hs
+++ b/src/GHC/SourceGen/Decl.hs
@@ -29,9 +29,7 @@ module GHC.SourceGen.Decl
     , derivingStock
     , derivingAnyclass
     , derivingNewtype
-#if MIN_VERSION_ghc(8,6,0)
     , derivingVia
-#endif
     , standaloneDeriving
     , standaloneDerivingStock
     , standaloneDerivingNewtype
@@ -51,7 +49,6 @@ module GHC.SourceGen.Decl
     , patSynBind
     ) where
 
-#if MIN_VERSION_ghc(9,0,0)
 import GHC (LexicalFixity(Prefix))
 import GHC.Data.Bag (listToBag)
 import GHC.Hs
@@ -64,15 +61,6 @@ import GHC (GhcPs, LayoutInfo (NoLayoutInfo))
 #else
 import GHC.Types.SrcLoc (LayoutInfo(NoLayoutInfo))
 #endif
-
-#else
-import BasicTypes (LexicalFixity(Prefix))
-import Bag (listToBag)
-import GHC.Hs.Extension (GhcPs)
-#endif
-#if !MIN_VERSION_ghc(8,6,0)
-import BasicTypes (DerivStrategy(..))
-#endif
 import GHC.Hs.Binds
 import GHC.Hs.Decls
 
@@ -89,26 +77,19 @@ import GHC.Hs.Type
     , HsSrcBang(..)
     , HsType(..)
     , LHsType
-#if MIN_VERSION_ghc(8,6,0)
     , HsWildCardBndrs (..)
-#endif
-#if MIN_VERSION_ghc(8,8,0)
     , HsArg(..)
-#endif
     , SrcStrictness(..)
     , SrcUnpackedness(..)
+    , hsUnrestricted
     )
 
 #if MIN_VERSION_ghc(9,10,0)
 import GHC.Parser.Annotation (AnnSortKey(..), EpAnn(..), EpLayout (EpNoLayout))
 #elif MIN_VERSION_ghc(9,2,0)
 import GHC.Parser.Annotation (AnnSortKey(..), EpAnn(..))
-#elif MIN_VERSION_ghc(8,10,0)
-import GHC.Hs.Extension (NoExtField(NoExtField))
-#elif MIN_VERSION_ghc(8,6,0)
-import GHC.Hs.Extension (NoExt(NoExt))
 #else
-import PlaceHolder (PlaceHolder(..))
+import GHC.Hs.Extension (NoExtField(NoExtField))
 #endif
 
 import GHC.SourceGen.Binds.Internal
@@ -190,14 +171,8 @@ class' context name vars decls
             , tcdCExt = (EpAnnNotUsed, NoAnnSortKey)
 #elif MIN_VERSION_ghc(9,2,0)
             , tcdCExt = (EpAnnNotUsed, NoAnnSortKey, NoLayoutInfo)
-#elif MIN_VERSION_ghc(9,0,0)
-            , tcdCExt = NoLayoutInfo
-#elif MIN_VERSION_ghc(8,10,0)
-            , tcdCExt = NoExtField
-#elif MIN_VERSION_ghc(8,6,0)
-            , tcdCExt = NoExt
 #else
-            , tcdFVs = PlaceHolder
+            , tcdCExt = NoLayoutInfo
 #endif
             , tcdLName = typeRdrName $ unqual name
             , tcdTyVars = mkQTyVars vars
@@ -264,10 +239,8 @@ instance' ty decls = noExt InstD  $ noExt ClsInstD $ ClsInstDecl
     , cid_ext = (Nothing, noAnn, NoAnnSortKey)
 #elif MIN_VERSION_ghc(9,2,0)
     , cid_ext = (EpAnnNotUsed, NoAnnSortKey)
-#elif MIN_VERSION_ghc(8,10,0)
+#else
     , cid_ext = NoExtField
-#elif MIN_VERSION_ghc(8,6,0)
-    , cid_ext = NoExt
 #endif
 #if MIN_VERSION_ghc(9,12,0)
     , cid_binds = [mkLocated b | InstBind b <- decls]
@@ -324,19 +297,6 @@ tyFamInst name params ty = tyFamInstD
     tyFamInstDecl = withEpAnnNotUsed TyFamInstDecl
     famEqn tycon bndrs pats = withEpAnnNotUsed FamEqn tycon bndrs (map HsValArg pats)
     eqn_bndrs = noExt HsOuterImplicit
-#elif MIN_VERSION_ghc(8,8,0)
-tyFamInst name params ty = tyFamInstD
-        $ tyFamInstDecl
-        $ famEqn
-            (typeRdrName name)
-            eqn_bndrs
-            (map mkLocated params)
-            Prefix
-            (mkLocated ty)
-  where
-    tyFamInstDecl = TyFamInstDecl . withPlaceHolder . noExt (withPlaceHolder HsIB)
-    famEqn tycon bndrs pats = noExt FamEqn tycon bndrs (map HsValArg  pats)
-    eqn_bndrs = Nothing
 #else
 tyFamInst name params ty = tyFamInstD
         $ tyFamInstDecl
@@ -348,7 +308,7 @@ tyFamInst name params ty = tyFamInstD
             (mkLocated ty)
   where
     tyFamInstDecl = TyFamInstDecl . withPlaceHolder . noExt (withPlaceHolder HsIB)
-    famEqn tycon _ = noExt FamEqn tycon
+    famEqn tycon bndrs pats = noExt FamEqn tycon bndrs (map HsValArg  pats)
     eqn_bndrs = Nothing
 #endif
 
@@ -571,11 +531,6 @@ strict f = f { strictness = SrcStrict }
 lazy :: Field -> Field
 lazy f = f { strictness = SrcLazy }
 
-#if !MIN_VERSION_ghc(9,0,0)
-hsUnrestricted :: a -> a
-hsUnrestricted = id
-#endif
-
 #if MIN_VERSION_ghc(9,14,0)
 renderField :: Field -> HsConDeclField GhcPs
 #else
@@ -605,10 +560,8 @@ renderCon98Decl name details =
     conDeclH98 = ConDeclH98 noAnn
 #elif MIN_VERSION_ghc(9,2,0)
     conDeclH98 = withEpAnnNotUsed ConDeclH98
-#elif MIN_VERSION_ghc(8,6,0)
-    conDeclH98 n = noExt ConDeclH98 n . builtLoc
 #else
-    conDeclH98 n _ _ = ConDeclH98 n Nothing
+    conDeclH98 n = noExt ConDeclH98 n . builtLoc
 #endif
 
 deriving' :: [HsType'] -> HsDerivingClause'
@@ -664,7 +617,6 @@ derivingAnyclass = derivingWay (Just strat)
     strat = AnyclassStrategy
 #endif
 
-#if MIN_VERSION_ghc(8,6,0)
 -- | A `DerivingVia` clause.
 --
 -- > deriving (Eq, Show) via T
@@ -681,7 +633,6 @@ derivingVia t = derivingWay (Just $ strat $ sigType t)
 #else
     strat = ViaStrategy
 #endif
-#endif
 
 standaloneDeriving :: HsType' -> HsDecl'
 standaloneDeriving = standaloneDerivingWay Nothing
@@ -729,12 +680,7 @@ standaloneDerivingWay way ty = noExt DerivD derivDecl
 #else
           withEpAnnNotUsed DerivDecl (hsWC $ sigType ty) (fmap builtLoc way) Nothing
 #endif
-        hsWC =
-#if MIN_VERSION_ghc(8,6,0)
-          noExt HsWC
-#else
-          id
-#endif
+        hsWC = noExt HsWC
 
 -- | Declares multiple pattern signatures of the same type.
 --
diff --git a/src/GHC/SourceGen/Expr.hs b/src/GHC/SourceGen/Expr.hs
index 3a0a0cd..c3b5336 100644
--- a/src/GHC/SourceGen/Expr.hs
+++ b/src/GHC/SourceGen/Expr.hs
@@ -52,11 +52,7 @@ import GHC.Hs.Type (
   )
 import GHC.Hs.Utils (mkHsIf)
 import Data.String (fromString)
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Types.SrcLoc (unLoc, GenLocated(..))
-#else
-import SrcLoc (unLoc, GenLocated(..))
-#endif
 
 #if MIN_VERSION_ghc(9,2,0)
 import GHC.Parser.Annotation (EpAnn(..))
@@ -191,10 +187,8 @@ do' :: [Stmt'] -> HsExpr'
 do' = withPlaceHolder
 #if MIN_VERSION_ghc(9,10,0)
         . HsDo noAnn (DoExpr Nothing)
-#elif MIN_VERSION_ghc(9,0,0)
-        . withEpAnnNotUsed HsDo (DoExpr Nothing)
 #else
-        . noExt HsDo DoExpr
+        . withEpAnnNotUsed HsDo (DoExpr Nothing)
 #endif
         . mkLocated . map (mkLocated . parenthesizeIfLet)
   where
@@ -202,13 +196,8 @@ do' = withPlaceHolder
   --   do let x = ...
   --      in x
   -- which is not valid Haskell.
-#if MIN_VERSION_ghc(8,6,0)
     parenthesizeIfLet (BodyStmt ext e@(L _ HsLet{}) x y)
         = BodyStmt ext (parExpr e) x y
-#else
-    parenthesizeIfLet (BodyStmt e@(L _ HsLet{}) x y tc)
-        = BodyStmt (parExpr e) x y tc
-#endif
     parenthesizeIfLet s = s
 
 -- | A list comprehension expression.
@@ -222,11 +211,7 @@ do' = withPlaceHolder
 listComp :: HsExpr' -> [Stmt'] -> HsExpr'
 listComp lastExpr stmts =
     let lastStmt = noExt LastStmt (mkLocated lastExpr) ret noSyntaxExpr
-#if MIN_VERSION_ghc(9,0,0)
         ret = Nothing
-#else
-        ret = False
-#endif
 #if MIN_VERSION_ghc(9,10,0)
      in withPlaceHolder . HsDo noAnn ListComp . mkLocated . map mkLocated $
             stmts ++ [lastStmt]
@@ -243,12 +228,8 @@ listComp lastExpr stmts =
 (@::@) :: HsExpr' -> HsType' -> HsExpr'
 #if MIN_VERSION_ghc(9,10,0)
 e @::@ t = ExprWithTySig noAnn (mkLocated e) (sigWcType t)
-#elif MIN_VERSION_ghc(8,8,0)
-e @::@ t = withEpAnnNotUsed ExprWithTySig (mkLocated e) (sigWcType t)
-#elif MIN_VERSION_ghc(8,6,0)
-e @::@ t = ExprWithTySig (sigWcType t) (builtLoc e)
 #else
-e @::@ t = ExprWithTySig (builtLoc e) (sigWcType t)
+e @::@ t = withEpAnnNotUsed ExprWithTySig (mkLocated e) (sigWcType t)
 #endif
 -- TODO: The Outputable instance prepends extra spaces; I'm not sure why.
 
@@ -264,12 +245,8 @@ tyApp e t = HsAppType (EpTok noSpanAnchor) e' t'
 tyApp e t = noExt HsAppType e' noHsTok t'
 #elif MIN_VERSION_ghc(9,2,0)
 tyApp e t = HsAppType builtSpan e' t'
-#elif MIN_VERSION_ghc(8,8,0)
-tyApp e t = noExt HsAppType e' t'
-#elif MIN_VERSION_ghc(8,6,0)
-tyApp e t = HsAppType t' e'
 #else
-tyApp e t = HsAppType e' t'
+tyApp e t = noExt HsAppType e' t'
 #endif
   where
     t' = wcType $ unLoc $ parenthesizeTypeForApp $ mkLocated t
@@ -286,9 +263,6 @@ recordConE c fs = (withPlaceHolder $ RecordCon noAnn (valueRdrName c))
 #else
 recordConE c fs = (withPlaceHolder $ withEpAnnNotUsed RecordCon (valueRdrName c))
 #endif
-#if !MIN_VERSION_ghc(8,6,0)
-                    noPostTcExpr
-#endif
 #if MIN_VERSION_ghc(9,12,0)
                     $ noExt HsRecFields
 #else
@@ -395,10 +369,8 @@ arithSeq :: ArithSeqInfo GhcPs -> HsExpr'
 arithSeq =
 #if MIN_VERSION_ghc(9,10,0)
     ArithSeq noAnn Nothing
-#elif MIN_VERSION_ghc(8,6,0)
-    withEpAnnNotUsed ArithSeq Nothing
 #else
-    ArithSeq noPostTcExpr Nothing
+    withEpAnnNotUsed ArithSeq Nothing
 #endif
 
 -- | An arithmetic sequence expression with a start value.
diff --git a/src/GHC/SourceGen/Expr/Internal.hs b/src/GHC/SourceGen/Expr/Internal.hs
index 1cb3488..d6496e8 100644
--- a/src/GHC/SourceGen/Expr/Internal.hs
+++ b/src/GHC/SourceGen/Expr/Internal.hs
@@ -8,11 +8,7 @@
 module GHC.SourceGen.Expr.Internal where
 
 import GHC.Hs.Expr
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Types.SrcLoc (unLoc)
-#else
-import SrcLoc (unLoc)
-#endif
 
 import GHC.SourceGen.Lit.Internal
 import GHC.SourceGen.Syntax.Internal
@@ -43,17 +39,11 @@ parExpr e = mkLocated $ withEpAnnNotUsed HsPar mkToken e mkToken
 parExpr = mkLocated . withEpAnnNotUsed HsPar
 #endif
 
-#if MIN_VERSION_ghc(8,6,0)
-#define WILD_EXT _
-#else
-#define WILD_EXT
-#endif
-
 needsExprForApp, needsExprForOp :: HsExpr' -> Bool
 needsExprForOp e = case e of
     -- TODO: more care for literals; only needed for negative numbers?
-    HsLit WILD_EXT l -> litNeedsParen l
-    HsOverLit WILD_EXT l -> overLitNeedsParen l
+    HsLit _ l -> litNeedsParen l
+    HsOverLit _ l -> overLitNeedsParen l
     HsLam{} -> True
 #if !MIN_VERSION_ghc(9,10,0)
     HsLamCase{} -> True
diff --git a/src/GHC/SourceGen/Lit.hs b/src/GHC/SourceGen/Lit.hs
index 6ddb617..2a90ef8 100644
--- a/src/GHC/SourceGen/Lit.hs
+++ b/src/GHC/SourceGen/Lit.hs
@@ -21,12 +21,9 @@ module GHC.SourceGen.Lit
 import GHC.Types.SourceText (mkTHFractionalLit, mkIntegralLit)
 import GHC.Data.FastString (fsLit)
 import GHC.Parser.Annotation (noAnn)
-#elif MIN_VERSION_ghc(9,0,0)
+#else
 import GHC.Types.Basic (mkFractionalLit, mkIntegralLit)
 import GHC.Data.FastString (fsLit)
-#else
-import BasicTypes (mkFractionalLit, mkIntegralLit)
-import FastString (fsLit)
 #endif
 import GHC.Hs.Lit
 import GHC.Hs.Expr (noExpr, noSyntaxExpr, HsExpr(..))
diff --git a/src/GHC/SourceGen/Lit/Internal.hs b/src/GHC/SourceGen/Lit/Internal.hs
index e88f8a0..456a118 100644
--- a/src/GHC/SourceGen/Lit/Internal.hs
+++ b/src/GHC/SourceGen/Lit/Internal.hs
@@ -9,10 +9,8 @@ module GHC.SourceGen.Lit.Internal where
 
 #if MIN_VERSION_ghc(9,2,0)
 import GHC.Types.SourceText (SourceText(NoSourceText), FractionalLit(..), IntegralLit(..))
-#elif MIN_VERSION_ghc(9,0,0)
-import GHC.Types.Basic (SourceText(NoSourceText), FractionalLit(..), IntegralLit(..))
 #else
-import BasicTypes (SourceText(NoSourceText), FractionalLit(..), IntegralLit(..))
+import GHC.Types.Basic (SourceText(NoSourceText), FractionalLit(..), IntegralLit(..))
 #endif
 import GHC.Hs.Lit
 import GHC.SourceGen.Syntax.Internal
diff --git a/src/GHC/SourceGen/Module.hs b/src/GHC/SourceGen/Module.hs
index 4a062ab..f2026b7 100644
--- a/src/GHC/SourceGen/Module.hs
+++ b/src/GHC/SourceGen/Module.hs
@@ -36,9 +36,7 @@ import GHC.Hs
     ( HsModule(..)
     , ImportDecl(..)
     , simpleImportDecl
-#if MIN_VERSION_ghc(8,10,0)
     , ImportDeclQualifiedStyle(..)
-#endif
 #if MIN_VERSION_ghc(9,2,0)
     , EpAnn(..)
 #endif
@@ -51,15 +49,11 @@ import GHC.Hs
     , LIEWrappedName
 #endif
     )
-#if MIN_VERSION_ghc(9,0,0) && !MIN_VERSION_ghc(9,6,0)
+#if !MIN_VERSION_ghc(9,6,0)
 import GHC.Types.SrcLoc (LayoutInfo(..))
 #endif
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Unit.Module (IsBootInterface(..))
 import GHC.Types.Name.Reader (RdrName)
-#else
-import RdrName (RdrName)
-#endif
 #if MIN_VERSION_ghc(9,4,0)
 import GHC.Types.PkgQual (RawPkgQual(..))
 #endif
@@ -101,9 +95,7 @@ module' name exports imports decls = HsModule
 #else
     , hsmodDeprecMessage = Nothing
     , hsmodHaddockModHeader = Nothing
-#  if MIN_VERSION_ghc(9,0,0)
     , hsmodLayout = NoLayoutInfo
-#  endif
 #  if MIN_VERSION_ghc(9,2,0)
     , hsmodAnn = EpAnnNotUsed
 #  endif
@@ -112,11 +104,7 @@ module' name exports imports decls = HsModule
 
 qualified' :: ImportDecl' -> ImportDecl'
 qualified' d = d { ideclQualified =
-#if MIN_VERSION_ghc(8,10,0)
     QualifiedPre
-#else
-    True
-#endif
 }
 
 as' :: ImportDecl' -> ModuleNameStr -> ImportDecl'
@@ -143,13 +131,7 @@ hiding d ies = d
 
 -- | Adds the @{-# SOURCE #-}@ pragma to an import.
 source :: ImportDecl' -> ImportDecl'
-source d = d { ideclSource =
-#if MIN_VERSION_ghc(9,0,0)
-    IsBoot
-#else
-    True
-#endif
-}
+source d = d { ideclSource = IsBoot }
 
 -- | Exports all methods and/or constructors.
 --
@@ -213,10 +195,7 @@ withEpAnnNotUsed' = ($ (Nothing, EpAnnNotUsed))
 #elif MIN_VERSION_ghc(9,2,0)
 withEpAnnNotUsed' :: (EpAnn ann -> a) -> a
 withEpAnnNotUsed' = withEpAnnNotUsed
-#elif MIN_VERSION_ghc(8,6,0)
-withEpAnnNotUsed' :: (NoExtField -> a) -> a
-withEpAnnNotUsed' = withEpAnnNotUsed
 #else
-withEpAnnNotUsed' :: a -> a
+withEpAnnNotUsed' :: (NoExtField -> a) -> a
 withEpAnnNotUsed' = withEpAnnNotUsed
 #endif
diff --git a/src/GHC/SourceGen/Name.hs b/src/GHC/SourceGen/Name.hs
index 3fa6056..cf7d7cc 100644
--- a/src/GHC/SourceGen/Name.hs
+++ b/src/GHC/SourceGen/Name.hs
@@ -28,17 +28,10 @@ module GHC.SourceGen.Name
     , moduleNameStrToString
     ) where
 
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Data.FastString (unpackFS)
 import GHC.Unit.Module (moduleNameString)
 import GHC.Types.Name.Occurrence (OccName, occNameFS, occNameSpace, isVarNameSpace)
 import GHC.Types.Name (Name, nameOccName)
-#else
-import FastString (unpackFS)
-import Module (moduleNameString)
-import OccName (OccName, occNameFS, occNameSpace, isVarNameSpace)
-import Name (Name, nameOccName)
-#endif
 import GHC.SourceGen.Name.Internal
 
 unqual :: OccNameStr -> RdrNameStr
diff --git a/src/GHC/SourceGen/Name/Internal.hs b/src/GHC/SourceGen/Name/Internal.hs
index d310415..e2e6199 100644
--- a/src/GHC/SourceGen/Name/Internal.hs
+++ b/src/GHC/SourceGen/Name/Internal.hs
@@ -11,17 +11,10 @@ import Data.Char (isAlphaNum, isUpper)
 import Data.Function (on)
 import Data.List (intercalate)
 import Data.String (IsString(..))
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Data.FastString (FastString, fsLit)
 import GHC.Unit.Module (mkModuleNameFS, ModuleName, moduleNameString)
 import GHC.Types.Name.Occurrence
 import GHC.Types.Name.Reader
-#else
-import FastString (FastString, fsLit)
-import Module (mkModuleNameFS, ModuleName, moduleNameString)
-import OccName
-import RdrName
-#endif
 
 #if MIN_VERSION_ghc(9,2,0)
 import GHC.Data.FastString (LexicalFastString(..))
@@ -29,10 +22,8 @@ import GHC.Data.FastString (LexicalFastString(..))
 
 #if MIN_VERSION_ghc(9,2,0)
 import GHC.Parser.Annotation (LocatedN)
-#elif MIN_VERSION_ghc(9,0,0)
-import GHC.Types.SrcLoc (Located)
 #else
-import SrcLoc (Located)
+import GHC.Types.SrcLoc (Located)
 #endif
 
 import GHC.SourceGen.Syntax.Internal (mkLocated)
diff --git a/src/GHC/SourceGen/Overloaded.hs b/src/GHC/SourceGen/Overloaded.hs
index c31780c..6e6f8f0 100644
--- a/src/GHC/SourceGen/Overloaded.hs
+++ b/src/GHC/SourceGen/Overloaded.hs
@@ -30,10 +30,11 @@ import GHC.Hs.Type
     , mkHsOpTy
 #endif
     )
-import GHC.Hs (IE(..), IEWrappedName(..))
-#if !MIN_VERSION_ghc(8,6,0)
-import PlaceHolder(PlaceHolder(..))
+import GHC.Hs (IE(..), IEWrappedName(..)
+#if MIN_VERSION_ghc(9,6,0)
+    , noExtField
 #endif
+    )
 
 import GHC.Hs
     ( HsExpr(..)
@@ -48,18 +49,11 @@ import GHC.Hs
 #if MIN_VERSION_ghc(9,10,0)
 import GHC.Parser.Annotation (AnnList (..), noAnn)
 #endif
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Types.Basic (Boxity(..))
 import GHC.Core.DataCon (dataConName)
 import GHC.Types.Name.Reader (nameRdrName)
 import GHC.Builtin.Types (consDataCon_RDR, nilDataCon, unitDataCon)
 import GHC.Types.Var (Specificity(..))
-#else
-import BasicTypes (Boxity(..))
-import DataCon (dataConName)
-import RdrName (nameRdrName)
-import TysWiredIn (consDataCon_RDR, nilDataCon, unitDataCon)
-#endif
 
 import GHC.SourceGen.Expr.Internal
 import GHC.SourceGen.Name.Internal
@@ -176,9 +170,6 @@ instance App HsExpr' where
         = withEpAnnNotUsed OpApp
             (parenthesizeExprForOp $ mkLocated x)
             (mkLocated $ var o)
-#if !MIN_VERSION_ghc(8,6,0)
-            PlaceHolder
-#endif
             (parenthesizeExprForOp $ mkLocated y)
 #endif
 #if MIN_VERSION_ghc(9,10,0)
@@ -256,10 +247,8 @@ instance HasTuple Pat' where
     tupleOf b ps =
 #if MIN_VERSION_ghc(9,10,0)
         TuplePat noAnn (map builtPat ps) b
-#elif MIN_VERSION_ghc(8,6,0)
-        withEpAnnNotUsed TuplePat (map builtPat ps) b
 #else
-        withEpAnnNotUsed TuplePat (map builtPat ps) b []
+        withEpAnnNotUsed TuplePat (map builtPat ps) b
 #endif
     unit = noExt VarPat unitDataConName
 
@@ -300,10 +289,8 @@ instance HasList HsExpr' where
 instance HasList Pat' where
 #if MIN_VERSION_ghc(9,10,0)
     list = ListPat noAnn . map builtPat
-#elif MIN_VERSION_ghc(8,6,0)
-    list = withEpAnnNotUsed ListPat . map builtPat
 #else
-    list ps = ListPat (map builtPat ps) PlaceHolder Nothing
+    list = withEpAnnNotUsed ListPat . map builtPat
 #endif
     nil = noExt VarPat nilDataConName
     cons = noExt VarPat $ mkLocated $ consDataCon_RDR
@@ -358,14 +345,11 @@ instance BVar HsTyVarBndr' where
     bvar = withEpAnnNotUsed UserTyVar HsBndrRequired . typeRdrName . UnqualStr
 instance BVar HsTyVarBndrS' where
     bvar = withEpAnnNotUsed UserTyVar SpecifiedSpec . typeRdrName . UnqualStr
-#elif MIN_VERSION_ghc(9,0,0)
+#else
 instance BVar HsTyVarBndr' where
   bvar = withEpAnnNotUsed UserTyVar () . typeRdrName . UnqualStr
 instance BVar HsTyVarBndrS' where
     bvar = withEpAnnNotUsed UserTyVar SpecifiedSpec . typeRdrName . UnqualStr
-#else
-instance BVar HsTyVarBndr' where
-    bvar = withEpAnnNotUsed UserTyVar . typeRdrName . UnqualStr
 #endif
 
 instance Var IE' where
diff --git a/src/GHC/SourceGen/Pat.hs b/src/GHC/SourceGen/Pat.hs
index 2b3eddc..964b0d8 100644
--- a/src/GHC/SourceGen/Pat.hs
+++ b/src/GHC/SourceGen/Pat.hs
@@ -68,10 +68,8 @@ conP c pats = conPat (valueRdrName c) (prefixCon (map (builtPat . parenthesize)
   where
 #if MIN_VERSION_ghc(9,10,0)
     conPat = ConPat noAnn
-#elif MIN_VERSION_ghc(9,0,0)
-    conPat = withEpAnnNotUsed ConPat
 #else
-    conPat = ConPatIn
+    conPat = withEpAnnNotUsed ConPat
 #endif
 #if !MIN_VERSION_ghc(9,14,0) && MIN_VERSION_ghc(9,2,0)
     prefixCon = PrefixCon []
@@ -91,10 +89,8 @@ recordConP :: RdrNameStr -> [(RdrNameStr, Pat')] -> Pat'
 recordConP c fs =
 #if MIN_VERSION_ghc(9,10,0)
   ConPat noAnn
-#elif MIN_VERSION_ghc(9,0,0)
-  withEpAnnNotUsed ConPat
 #else
-  ConPatIn
+  withEpAnnNotUsed ConPat
 #endif
   (valueRdrName c)
 #if MIN_VERSION_ghc(9,12,0)
@@ -161,10 +157,6 @@ lazyP = withEpAnnNotUsed LazyPat . builtPat . parenthesize
 sigP :: Pat' -> HsType' -> Pat'
 #if MIN_VERSION_ghc(9,10,0)
 sigP p t = SigPat noAnn (builtPat p) (patSigType t)
-#elif MIN_VERSION_ghc(8,8,0)
-sigP p t = withEpAnnNotUsed SigPat (builtPat p) (patSigType t)
-#elif MIN_VERSION_ghc(8,6,0)
-sigP p t = SigPat (patSigType t) (builtPat p)
 #else
-sigP p t = SigPatIn (builtPat p) (patSigType t)
+sigP p t = withEpAnnNotUsed SigPat (builtPat p) (patSigType t)
 #endif
diff --git a/src/GHC/SourceGen/Pat/Internal.hs b/src/GHC/SourceGen/Pat/Internal.hs
index 37a18e8..b889af2 100644
--- a/src/GHC/SourceGen/Pat/Internal.hs
+++ b/src/GHC/SourceGen/Pat/Internal.hs
@@ -5,13 +5,8 @@ import GHC.Hs.Pat (Pat(..))
 #if MIN_VERSION_ghc(9,10,0)
 import GHC.Parser.Annotation (EpToken(..), noSpanAnchor)
 #endif
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Hs.Type (HsConDetails(..))
 import GHC.Types.SrcLoc (unLoc)
-#else
-import GHC.Hs.Type (HsConDetails(..))
-import SrcLoc (unLoc)
-#endif
 
 import GHC.SourceGen.Lit.Internal (litNeedsParen, overLitNeedsParen)
 import GHC.SourceGen.Syntax.Internal
@@ -25,34 +20,17 @@ parenthesize p
 
 
 needsPar :: Pat' -> Bool
-#if MIN_VERSION_ghc(8,6,0)
 needsPar (LitPat _ l) = litNeedsParen l
 needsPar (NPat _ l _ _) = overLitNeedsParen $ unLoc l
-#else
-needsPar (LitPat l) = litNeedsParen l
-needsPar (NPat l _ _ _) = overLitNeedsParen $ unLoc l
-#endif
 #if MIN_VERSION_ghc(9,14,0)
 needsPar (ConPat _ _ (PrefixCon xs)) = not $ null xs
 #elif MIN_VERSION_ghc(9,2,0)
 needsPar (ConPat _ _ (PrefixCon _ xs)) = not $ null xs
-#elif MIN_VERSION_ghc(9,0,0)
-needsPar (ConPat _ _ (PrefixCon xs)) = not $ null xs
 #else
-needsPar (ConPatIn _ (PrefixCon xs)) = not $ null xs
+needsPar (ConPat _ _ (PrefixCon xs)) = not $ null xs
 #endif
-#if MIN_VERSION_ghc(9,0,0)
 needsPar (ConPat _ _ (InfixCon _ _)) = True
-#else
-needsPar (ConPatIn _ (InfixCon _ _)) = True
-needsPar ConPatOut{} = True
-#endif
-#if MIN_VERSION_ghc(8,6,0)
 needsPar SigPat{} = True
-#else
-needsPar SigPatIn{} = True
-needsPar SigPatOut{} = True
-#endif
 needsPar _ = False
 
 parPat :: Pat' -> Pat'
diff --git a/src/GHC/SourceGen/Pretty.hs b/src/GHC/SourceGen/Pretty.hs
index 4e17e00..d48ba5a 100644
--- a/src/GHC/SourceGen/Pretty.hs
+++ b/src/GHC/SourceGen/Pretty.hs
@@ -25,10 +25,7 @@ hPutPpr :: Outputable a => Handle -> a -> Ghc ()
 hPutPpr h x = do
     dflags <- getDynFlags
     liftIO $ printForUser dflags h neverQualify
-#if MIN_VERSION_ghc(9,0,1)
-        AllTheWay
-#endif
-            $ ppr x
+        AllTheWay $ ppr x
 
 putPpr :: Outputable a => a -> Ghc ()
 putPpr = hPutPpr stdout
diff --git a/src/GHC/SourceGen/Syntax/Internal.hs b/src/GHC/SourceGen/Syntax/Internal.hs
index b8f16d9..6e17d31 100644
--- a/src/GHC/SourceGen/Syntax/Internal.hs
+++ b/src/GHC/SourceGen/Syntax/Internal.hs
@@ -34,13 +34,7 @@ import GHC.Hs
     , LHsSigWcType
     , LHsWcType
     , TyFamInstDecl
-#if !MIN_VERSION_ghc(8,8,0)
-    , LHsRecField
-    , LHsRecUpdField
-#endif
-#if MIN_VERSION_ghc(9,0,0)
     , HsPatSigType
-#endif
 #if MIN_VERSION_ghc(9,2,0)
     , HsConDeclH98Details
 #else
@@ -48,22 +42,13 @@ import GHC.Hs
 #endif
     )
 import GHC.Hs.Binds (Sig, HsLocalBinds)
-#if MIN_VERSION_ghc(8,6,0)
 import GHC.Hs.Decls (DerivStrategy)
-#else
-import BasicTypes (DerivStrategy)
-#endif
 import GHC.Hs.Decls (HsDerivingClause)
 import GHC.Hs.Pat
 #if MIN_VERSION_ghc(9,10,0)
 import Language.Haskell.Syntax.Extension (NoGhcTc)
 #endif
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Types.SrcLoc (SrcSpan, Located, GenLocated(..), mkGeneralSrcSpan)
-#else
-import RdrName (RdrName)
-import SrcLoc (SrcSpan, Located, GenLocated(..), mkGeneralSrcSpan)
-#endif
 
 #if MIN_VERSION_ghc(9,2,0) && !MIN_VERSION_ghc(9,6,0)
 import GHC.Parser.Annotation
@@ -75,30 +60,15 @@ import GHC.Parser.Annotation
     )
 #endif
 
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Types.Basic (PromotionFlag(..))
-#elif MIN_VERSION_ghc(8,8,0)
-import BasicTypes (PromotionFlag(..))
-#else
-import GHC.Hs.Type (Promoted(..))
-#endif
 
 #if MIN_VERSION_ghc(9,8,0)
 import GHC.Hs.Type (HsBndrVis)
 #endif
 
-#if MIN_VERSION_ghc(8,10,0)
 import qualified GHC.Hs as GHC
-#elif MIN_VERSION_ghc(8,6,0)
-import qualified GHC.Hs.Extension as GHC
-#else
-import qualified HsExtension as GHC
-import qualified PlaceHolder as GHC
-#endif
 
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Types.Var (Specificity)
-#endif
 
 #if MIN_VERSION_ghc(9,4,0)
 import GHC.Parser.Annotation
@@ -106,30 +76,13 @@ import GHC.Parser.Annotation
 
 import GHC.Hs.Extension (GhcPs)
 
-#if MIN_VERSION_ghc(8,10,0)
 type NoExtField = GHC.NoExtField
-#elif MIN_VERSION_ghc(8,6,0)
-type NoExtField = GHC.NoExt
-#endif
 
-#if MIN_VERSION_ghc(8,10,0)
 noExt :: (NoExtField -> a) -> a
 noExt = ($ GHC.NoExtField)
-#elif MIN_VERSION_ghc(8,6,0)
-noExt :: (NoExtField -> a) -> a
-noExt = ($ GHC.NoExt)
-#else
-noExt :: a -> a
-noExt = id
-#endif
 
-#if MIN_VERSION_ghc(8,6,0)
 noExtOrPlaceHolder :: (NoExtField -> a) -> a
 noExtOrPlaceHolder = noExt
-#else
-noExtOrPlaceHolder :: (GHC.PlaceHolder -> a) -> a
-noExtOrPlaceHolder = withPlaceHolder
-#endif
 
 #if MIN_VERSION_ghc(9,10,0)
 withEpAnnNotUsed :: a -> a
@@ -137,12 +90,9 @@ withEpAnnNotUsed = id
 #elif MIN_VERSION_ghc(9,2,0)
 withEpAnnNotUsed :: (EpAnn ann -> a) -> a
 withEpAnnNotUsed = ($ EpAnnNotUsed)
-#elif MIN_VERSION_ghc(8,6,0)
+#else
 withEpAnnNotUsed :: (NoExtField -> a) -> a
 withEpAnnNotUsed = noExt
-#else
-withEpAnnNotUsed :: a -> a
-withEpAnnNotUsed = id
 #endif
 
 #if MIN_VERSION_ghc(9,10,0)
@@ -151,40 +101,24 @@ withNoAnnSortKey = ($ NoAnnSortKey)
 #elif MIN_VERSION_ghc(9,2,0)
 withNoAnnSortKey :: (AnnSortKey -> a) -> a
 withNoAnnSortKey = ($ NoAnnSortKey)
-#elif MIN_VERSION_ghc(8,6,0)
+#else
 withNoAnnSortKey :: (NoExtField -> a) -> a
 withNoAnnSortKey = noExt
-#else
-withNoAnnSortKey :: a -> a
-withNoAnnSortKey = id
 #endif
 
 #if MIN_VERSION_ghc(9,2,0)
 withEmptyEpAnnComments :: (EpAnnComments -> a) -> a
 withEmptyEpAnnComments = ($ emptyComments)
-#elif MIN_VERSION_ghc(8,6,0)
+#else
 withEmptyEpAnnComments :: (NoExtField -> a) -> a
 withEmptyEpAnnComments = noExt
-#else
-withEmptyEpAnnComments :: a -> a
-withEmptyEpAnnComments = id
 #endif
 
-#if MIN_VERSION_ghc(8,6,0)
 withPlaceHolder :: a -> a
 withPlaceHolder = id
-#else
-withPlaceHolder :: (GHC.PlaceHolder -> a) -> a
-withPlaceHolder = ($ GHC.PlaceHolder)
-#endif
 
-#if MIN_VERSION_ghc(8,6,0)
 withPlaceHolders :: a -> a
 withPlaceHolders = id
-#else
-withPlaceHolders :: ([GHC.PlaceHolder] -> a) -> a
-withPlaceHolders = ($ [])
-#endif
 
 builtSpan :: SrcSpan
 builtSpan = mkGeneralSrcSpan "<ghc-source-gen>"
@@ -200,7 +134,6 @@ type SrcSpanAnn ann = GHC.SrcSpanAnn' (EpAnn ann)
 type SrcSpanAnn ann = SrcSpan
 #endif
 
-
 #if MIN_VERSION_ghc(9,10,0)
 mkLocated :: (NoAnn ann) => a -> GenLocated (SrcSpanAnn ann) a
 mkLocated = L (EpAnn (spanAsAnchor builtSpan) noAnn emptyComments)
@@ -212,26 +145,16 @@ mkLocated :: a -> GenLocated (SrcSpanAnn ann) a
 mkLocated = L builtSpan
 #endif
 
--- In GHC-8.8.* (but not >=8.10 or <=8.6), source locations for Pat aren't
--- stored in each node, and LPat is a synonym for Pat.
 builtPat :: Pat' -> LPat'
 #if MIN_VERSION_ghc(9,2,0)
 builtPat = mkLocated
-#elif MIN_VERSION_ghc(8,8,0) && !MIN_VERSION_ghc(8,10,0)
-builtPat = id
 #else
 builtPat = builtLoc
 #endif
 
-#if MIN_VERSION_ghc(8,8,0)
 promoted, notPromoted :: PromotionFlag
 promoted = IsPromoted
 notPromoted = NotPromoted
-#else
-promoted, notPromoted :: Promoted
-promoted = Promoted
-notPromoted = NotPromoted
-#endif
 
 -- TODO: these Haddock cross-references don't link to the actual
 -- definition, only to the module they come from.  I think it's
@@ -302,16 +225,13 @@ type IE' = IE GhcPs
 #if MIN_VERSION_ghc(9,8,0)
 type HsTyVarBndr' = HsTyVarBndr (HsBndrVis GhcPs) GhcPs
 type HsTyVarBndrS' = HsTyVarBndr Specificity GhcPs
-#elif MIN_VERSION_ghc(9,0,0)
+#else
 type HsTyVarBndr' = HsTyVarBndr () GhcPs
 type HsTyVarBndrS' = HsTyVarBndr Specificity GhcPs
-#else
-type HsTyVarBndr' = HsTyVarBndr GhcPs
-type HsTyVarBndrS' = HsTyVarBndr GhcPs
 #endif
 
 type HsLit' = HsLit GhcPs
-#if MIN_VERSION_ghc(9,0,0) && !MIN_VERSION_ghc(9,6,0)
+#if !MIN_VERSION_ghc(9,6,0)
 type HsModule' = HsModule
 #else
 type HsModule' = HsModule GhcPs
@@ -322,10 +242,8 @@ type HsValBinds' = HsValBinds GhcPs
 type Sig' = Sig GhcPs
 #if MIN_VERSION_ghc(9,10,0)
 type HsMatchContext' = HsMatchContext (GHC.LIdP (NoGhcTc GhcPs))
-#elif MIN_VERSION_ghc(9,0,0)
-type HsMatchContext' = HsMatchContext GhcPs
 #else
-type HsMatchContext' = HsMatchContext RdrName
+type HsMatchContext' = HsMatchContext GhcPs
 #endif
 type Match' = Match GhcPs
 type MatchGroup' = MatchGroup GhcPs
@@ -354,17 +272,9 @@ type LHsRecUpdField' = LHsRecUpdField GhcPs
 type LPat' = LPat GhcPs
 type TyFamInstDecl' = TyFamInstDecl GhcPs
 
-#if MIN_VERSION_ghc(8,6,0)
 type DerivStrategy' = DerivStrategy GhcPs
-#else
-type DerivStrategy' = DerivStrategy
-#endif
 
-#if MIN_VERSION_ghc(9,0,0)
 type HsPatSigType' = HsPatSigType GhcPs
-#else
-type HsPatSigType' = LHsSigWcType'
-#endif
 
 #if MIN_VERSION_ghc(9,2,0)
 type LIdP = GHC.LIdP GHC.GhcPs
diff --git a/src/GHC/SourceGen/Type.hs b/src/GHC/SourceGen/Type.hs
index b90bdd3..17be2cf 100644
--- a/src/GHC/SourceGen/Type.hs
+++ b/src/GHC/SourceGen/Type.hs
@@ -22,12 +22,8 @@ module GHC.SourceGen.Type
     ) where
 
 import Data.String (fromString)
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Hs.Type
 import GHC.Parser.Annotation
-#else
-import GHC.Hs.Type
-#endif
 
 #if MIN_VERSION_ghc(9,4,0)
 import Language.Haskell.Syntax.Extension
@@ -96,11 +92,9 @@ a --> b =
 #elif MIN_VERSION_ghc(9,4,0)
      withEpAnnNotUsed HsFunTy
          (HsUnrestrictedArrow mkUniToken)
-#elif MIN_VERSION_ghc(9,0,0)
-     withEpAnnNotUsed HsFunTy
-         (HsUnrestrictedArrow NormalSyntax)
 #else
      withEpAnnNotUsed HsFunTy
+         (HsUnrestrictedArrow NormalSyntax)
 #endif
          (parenthesizeTypeForFun $ mkLocated a) (mkLocated b)
 
@@ -124,19 +118,10 @@ forall' ts t =
 forall' ts = noExt hsForAllTy (map mkLocated ts) . mkLocated
   where
     hsForAllTy x = HsForAllTy x . withEpAnnNotUsed mkHsForAllInvisTele
-#elif MIN_VERSION_ghc(9,0,0)
-forall' ts = noExt hsForAllTy (map mkLocated ts) . mkLocated
-  where
-    hsForAllTy x = HsForAllTy x . mkHsForAllInvisTele
-#elif MIN_VERSION_ghc(8,10,0)
-forall' ts = noExt hsForAllTy (map mkLocated ts) . mkLocated
-  where
-    fvf = ForallInvis -- "Invisible" forall, i.e., with a dot
-    hsForAllTy x = HsForAllTy x fvf
 #else
 forall' ts = noExt hsForAllTy (map mkLocated ts) . mkLocated
   where
-    hsForAllTy = HsForAllTy
+    hsForAllTy x = HsForAllTy x . mkHsForAllInvisTele
 #endif
 
 -- | Qualify a type with constraints.
@@ -175,11 +160,8 @@ kindedVar v t =
             withEpAnnNotUsed KindedTyVar
                 HsBndrRequired
                 (typeRdrName $ UnqualStr v) (mkLocated t)
-#elif MIN_VERSION_ghc(9,0,0)
-            withEpAnnNotUsed KindedTyVar
-                ()
-                (typeRdrName $ UnqualStr v) (mkLocated t)
 #else
             withEpAnnNotUsed KindedTyVar
+                ()
                 (typeRdrName $ UnqualStr v) (mkLocated t)
 #endif
diff --git a/src/GHC/SourceGen/Type/Internal.hs b/src/GHC/SourceGen/Type/Internal.hs
index 3f53537..f869cc2 100644
--- a/src/GHC/SourceGen/Type/Internal.hs
+++ b/src/GHC/SourceGen/Type/Internal.hs
@@ -9,13 +9,8 @@ module GHC.SourceGen.Type.Internal where
 
 import GHC.Hs (GhcPs)
 
-#if MIN_VERSION_ghc(9,0,0)
 import GHC.Hs.Type as Types
 import GHC.Types.SrcLoc (unLoc)
-#else
-import GHC.Hs.Type as Types
-import SrcLoc (unLoc)
-#endif
 
 #if MIN_VERSION_ghc(9,10,0)
 import GHC.Parser.Annotation (AnnParen, noAnn, noSpanAnchor)
@@ -84,8 +79,6 @@ patSigType :: HsType' -> HsPatSigType'
 patSigType = mkHsPatSigType noAnn . mkLocated
 #elif MIN_VERSION_ghc(9,2,0)
 patSigType = withEpAnnNotUsed mkHsPatSigType . mkLocated
-#elif MIN_VERSION_ghc(9,0,0)
-patSigType = mkHsPatSigType . builtLoc
 #else
-patSigType = sigWcType
+patSigType = mkHsPatSigType . builtLoc
 #endif
diff --git a/stack.yaml b/stack.yaml
deleted file mode 100644
index 4efc954..0000000
--- a/stack.yaml
+++ /dev/null
@@ -1,13 +0,0 @@
-# Copyright 2019 Google LLC
-#
-# Use of this source code is governed by a BSD-style
-# license that can be found in the LICENSE file or at
-# https://developers.google.com/open-source/licenses/bsd
-
-resolver: lts-18.28
-packages:
-- .
-- ghc-show-ast
-
-ghc-options:
-  "$locals": -Wall -Werror
diff --git a/tests/name_test.hs b/tests/name_test.hs
index c7436ae..88bf93c 100644
--- a/tests/name_test.hs
+++ b/tests/name_test.hs
@@ -4,11 +4,7 @@ module Main (main) where
 
 import GHC.SourceGen.Name
 
-#if MIN_VERSION_ghc(9,0,1)
 import GHC.Types.Name.Occurrence
-#else
-import OccName
-#endif
 
 import Data.List (intercalate)
 import Data.String (fromString)