diff --git a/hls-haddock-comments-plugin.cabal b/hls-haddock-comments-plugin.cabal
--- a/hls-haddock-comments-plugin.cabal
+++ b/hls-haddock-comments-plugin.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.4
 name:               hls-haddock-comments-plugin
-version:            1.0.0.1
+version:            1.0.0.2
 synopsis:           Haddock comments plugin for Haskell Language Server
 description:
   Please see the README on GitHub at <https://github.com/haskell/haskell-language-server>
@@ -25,11 +25,11 @@
     -Wno-unticked-promoted-constructors
 
   build-depends:
-    , base                  >=4.12    && <5
+    , base                  >=4.12 && <5
     , containers
     , ghc
     , ghc-exactprint
-    , ghcide                ^>=1.2
+    , ghcide                >=1.2  && <1.5
     , hls-plugin-api        ^>=1.1
     , lsp-types
     , text
@@ -48,8 +48,7 @@
   ghc-options:      -threaded -rtsopts -with-rtsopts=-N
   build-depends:
     , base
-    , bytestring
     , filepath
     , hls-haddock-comments-plugin
-    , hls-test-utils  ^>= 1.0
+    , hls-test-utils               ^>=1.0
     , text
diff --git a/src/Ide/Plugin/HaddockComments.hs b/src/Ide/Plugin/HaddockComments.hs
--- a/src/Ide/Plugin/HaddockComments.hs
+++ b/src/Ide/Plugin/HaddockComments.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP                       #-}
 {-# LANGUAGE ExistentialQuantification #-}
 {-# LANGUAGE FlexibleContexts          #-}
 {-# LANGUAGE NamedFieldPuns            #-}
@@ -90,7 +91,11 @@
     isFresh Ann {annsDP} = null [() | (AnnComment _, _) <- annsDP]
     collectKeys = keyFromTyVar 0
 
+#if MIN_VERSION_ghc(9,0,0)
+    comment = mkComment "-- ^ " badRealSrcSpan
+#else
     comment = mkComment "-- ^ " noSrcSpan
+#endif
     dp = [(AnnComment comment, DP (0, 1)), (G AnnRarrow, DP (1, 2))]
 
 genForRecord :: GenComments
@@ -109,7 +114,11 @@
 
     collectKeys = keyFromCon
 
+#if MIN_VERSION_ghc(9,0,0)
+    comment = mkComment "-- | " badRealSrcSpan
+#else
     comment = mkComment "-- | " noSrcSpan
+#endif
 
 -----------------------------------------------------------------------------
 
@@ -131,7 +140,7 @@
 
 toRange :: SrcSpan -> Maybe Range
 toRange src
-  | (RealSrcSpan s) <- src,
+  | (OldRealSrcSpan s) <- src,
     range' <- realSrcSpanToRange s =
     Just range'
   | otherwise = Nothing
@@ -146,7 +155,12 @@
 -----------------------------------------------------------------------------
 
 keyFromTyVar :: Int -> LHsType GhcPs -> [AnnKey]
+#if MIN_VERSION_ghc(9,0,0)
+-- GHC9 HsFunTy has 4 arguments, we could extract this
+keyFromTyVar dep c@(L _ (HsFunTy _ _ x y))
+#else
 keyFromTyVar dep c@(L _ (HsFunTy _ x y))
+#endif
   | dep < 1 = mkAnnKey c : keyFromTyVar dep x ++ keyFromTyVar dep y
   | otherwise = []
 keyFromTyVar dep (L _ t@HsForAllTy {}) = keyFromTyVar dep (hst_body t)
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -1,21 +1,16 @@
-{-# LANGUAGE DataKinds                #-}
 {-# LANGUAGE DisambiguateRecordFields #-}
-{-# LANGUAGE GADTs                    #-}
 {-# LANGUAGE NamedFieldPuns           #-}
 {-# LANGUAGE OverloadedStrings        #-}
 {-# LANGUAGE TypeOperators            #-}
 {-# LANGUAGE ViewPatterns             #-}
 
 module Main
-  ( main,
-  )
-where
+  ( main
+  ) where
 
-import qualified Data.ByteString.Lazy       as LBS
 import           Data.Foldable              (find)
 import           Data.Maybe                 (mapMaybe)
 import           Data.Text                  (Text)
-import           Data.Text.Encoding         (encodeUtf8)
 import qualified Ide.Plugin.HaddockComments as HaddockComments
 import           System.FilePath            ((<.>), (</>))
 import           Test.Hls
@@ -23,40 +18,34 @@
 main :: IO ()
 main = defaultTestRunner tests
 
-plugin :: PluginDescriptor IdeState
-plugin = HaddockComments.descriptor "haddockComments"
+haddockCommentsPlugin :: PluginDescriptor IdeState
+haddockCommentsPlugin = HaddockComments.descriptor "haddockComments"
 
 tests :: TestTree
 tests =
   testGroup
     "haddock comments"
-    [ goldenTest "HigherRankFunction" Signature 4 6,
-      goldenTest "KindSigFunction" Signature 9 10,
-      goldenTest "MultivariateFunction" Signature 4 8,
-      goldenTest "QualFunction" Signature 2 10,
-      goldenTest "Record" Record 7 2,
+    [ goldenWithHaddockComments "HigherRankFunction" Signature 4 6,
+      goldenWithHaddockComments "KindSigFunction" Signature 9 10,
+      goldenWithHaddockComments "MultivariateFunction" Signature 4 8,
+      goldenWithHaddockComments "QualFunction" Signature 2 10,
+      goldenWithHaddockComments "Record" Record 7 2,
       expectedNothing "ConstFunction" Signature 2 2,
       expectedNothing "StaleFunction" Signature 3 3,
       expectedNothing "StaleRecord" Record 3 12
     ]
 
-goldenTest :: FilePath -> GenCommentsType -> Int -> Int -> TestTree
-goldenTest fp (toTitle -> expectedTitle) l c = goldenGitDiff (fp <> " (golden)") goldenFilePath $
-  runSessionWithServer plugin haddockCommentsPath $ do
-    doc <- openDoc hsFilePath "haskell"
+goldenWithHaddockComments :: FilePath -> GenCommentsType -> Int -> Int -> TestTree
+goldenWithHaddockComments fp (toTitle -> expectedTitle) l c =
+  goldenWithHaskellDoc haddockCommentsPlugin (fp <> " (golden)") testDataDir fp "expected" "hs" $ \doc -> do
     actions <- getCodeActions doc (Range (Position l c) (Position l $ succ c))
     case find ((== Just expectedTitle) . caTitle) actions of
-      Just (InR x) -> do
-        executeCodeAction x
-        LBS.fromStrict . encodeUtf8 <$> documentContents doc
-      _ -> liftIO $ assertFailure "Unable to find CodeAction"
-  where
-    hsFilePath = fp <.> "hs"
-    goldenFilePath = haddockCommentsPath </> fp <.> "expected" <.> "hs"
+      Just (InR x) -> executeCodeAction x
+      _            -> liftIO $ assertFailure "Unable to find CodeAction"
 
 expectedNothing :: FilePath -> GenCommentsType -> Int -> Int -> TestTree
 expectedNothing fp (toTitle -> expectedTitle) l c = testCase fp $
-  runSessionWithServer plugin haddockCommentsPath $ do
+  runSessionWithServer haddockCommentsPlugin testDataDir $ do
     doc <- openDoc (fp <.> "hs") "haskell"
     titles <- mapMaybe caTitle <$> getCodeActions doc (Range (Position l c) (Position l $ succ c))
     liftIO $ expectedTitle `notElem` titles @? "Unexpected CodeAction"
@@ -71,6 +60,6 @@
 caTitle (InR CodeAction {_title}) = Just _title
 caTitle _                         = Nothing
 
-haddockCommentsPath :: String
-haddockCommentsPath = "test" </> "testdata"
+testDataDir :: String
+testDataDir = "test" </> "testdata"