diff --git a/CHANGES.txt b/CHANGES.txt
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,5 +1,7 @@
 Changelog for record-dot-preprocessor
 
+0.2.14, released 2022-02-11
+    #48, do not derive HasField for existentials
 0.2.13, released 2021-11-03
     #46, make sure [a|b/|] gets treated as quasi quotes
 0.2.12, released 2021-09-01
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright Neil Mitchell 2018-2021.
+Copyright Neil Mitchell 2018-2022.
 
 Licensed under either of:
 
diff --git a/examples/Both.hs b/examples/Both.hs
--- a/examples/Both.hs
+++ b/examples/Both.hs
@@ -2,6 +2,8 @@
 
 {-# OPTIONS_GHC -Werror -Wall -Wno-type-defaults -Wno-partial-type-signatures -Wincomplete-record-updates -Wno-unused-top-binds #-} -- can we produce -Wall clean code
 {-# LANGUAGE PartialTypeSignatures, GADTs, StandaloneDeriving, DataKinds, KindSignatures #-} -- also tests we put language extensions before imports
+-- 8.8+ doesn't need it to be set explicitly
+{-# LANGUAGE ExistentialQuantification #-}
 
 import Control.Exception
 import Data.Version
@@ -217,6 +219,16 @@
     C (Nullable c) a = C c (Maybe a)
     C f a = f a
 
+-- Existential typed field xc' need to be omitted from types, otherwise
+-- compiler produce following error:
+--    • Illegal instance declaration for
+--        ‘GHC.Records.Extra.HasField "xc'" (Existential a) aplg’
+--        The liberal coverage condition fails in class ‘GHC.Records.Extra.HasField’
+--          for functional dependency: ‘x r -> a’
+--        Reason: lhs types ‘"xc'"’, ‘Existential a’
+--          do not jointly determine rhs type ‘aplg’
+--        Un-determined variable: aplg
+data Existential a = forall b. Bar { xa :: a, xb :: !a, xc' :: b }
 
 data Foo9 f = Foo9 {
   bar :: C f Int,
diff --git a/plugin/Compat.hs b/plugin/Compat.hs
--- a/plugin/Compat.hs
+++ b/plugin/Compat.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE ImplicitParams #-}
 {- HLINT ignore "Use camelCase" -}
 
 -- | Module containing the plugin.
@@ -8,16 +10,28 @@
 #if __GLASGOW_HASKELL__ < 900
 import BasicTypes
 import TcEvidence
+import RnTypes as Compat
+import UniqSupply
 #else
 import GHC.Types.Basic
 import GHC.Unit.Types
 import GHC.Parser.Annotation
+import GHC.Rename.HsType as Compat
+import GHC.Types.Unique.Supply
 #endif
 #if __GLASGOW_HASKELL__ < 810
 import HsSyn as Compat
 #else
 import GHC.Hs as Compat
 #endif
+#if __GLASGOW_HASKELL__ < 808
+import System.IO.Unsafe as Compat (unsafePerformIO)
+import TcRnTypes
+import IOEnv
+import DynFlags
+import HscTypes
+#endif
+import Data.IORef as Compat
 
 ---------------------------------------------------------------------
 -- UTILITIES
@@ -130,4 +144,29 @@
 qualifiedImplicitImport x = noL $ ImportDecl noE NoSourceText (noL x) Nothing NotBoot False
     QualifiedPost {- qualified -} True {- implicit -} Nothing Nothing
 
+#endif
+
+type PluginEnv = (?hscenv :: HscEnv, ?uniqSupply :: IORef UniqSupply)
+
+dropRnTraceFlags :: HscEnv -> HscEnv
+#if __GLASGOW_HASKELL__ < 808
+dropRnTraceFlags env@HscEnv{hsc_dflags = dflags} =  env{hsc_dflags = dopt_unset dflags Opt_D_dump_rn_trace}
+#else
+dropRnTraceFlags = id
+#endif
+
+freeTyVars :: PluginEnv => LHsType GhcPs -> [Located RdrName]
+#if __GLASGOW_HASKELL__ < 808
+{-# NOINLINE freeTyVars #-}
+freeTyVars  = freeKiTyVarsAllVars . runRnM . extractHsTyRdrTyVars
+  where
+    runRnM :: RnM a -> a
+    runRnM rnm = unsafePerformIO $ do
+      let env = Env ?hscenv ?uniqSupply unused unused
+      runIOEnv env rnm
+    unused = error "never called"
+#elif __GLASGOW_HASKELL__ < 810
+freeTyVars = freeKiTyVarsAllVars . extractHsTyRdrTyVars
+#else
+freeTyVars = extractHsTyRdrTyVars
 #endif
diff --git a/plugin/RecordDotPreprocessor.hs b/plugin/RecordDotPreprocessor.hs
--- a/plugin/RecordDotPreprocessor.hs
+++ b/plugin/RecordDotPreprocessor.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE RecordWildCards, ViewPatterns, NamedFieldPuns, OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards, ViewPatterns, NamedFieldPuns, OverloadedStrings, LambdaCase #-}
+{-# LANGUAGE ImplicitParams, ScopedTypeVariables #-}
 {- HLINT ignore "Use camelCase" -}
 
 -- | Module containing the plugin.
@@ -13,27 +14,36 @@
 #if __GLASGOW_HASKELL__ < 900
 import Bag
 import qualified GhcPlugins as GHC
+import qualified HscMain
 import qualified PrelNames as GHC
 import SrcLoc
 #else
 import GHC.Data.Bag
 import qualified GHC.Driver.Plugins as GHC
 import qualified GHC.Driver.Types as GHC
+import qualified GHC.Driver.Main as HscMain
 import qualified GHC.Builtin.Names as GHC
 import qualified GHC.Plugins as GHC
 import GHC.Types.SrcLoc
 #endif
 
-
 ---------------------------------------------------------------------
 -- PLUGIN WRAPPER
 
 -- | GHC plugin.
 plugin :: GHC.Plugin
 plugin = GHC.defaultPlugin
-    { GHC.parsedResultAction = \_cliOptions _modSummary x -> pure x{GHC.hpm_module = onModule <$> GHC.hpm_module x}
+    { GHC.parsedResultAction = parsedResultAction
     , GHC.pluginRecompile = GHC.purePlugin
     }
+    where
+        parsedResultAction _cliOptions _modSummary x = do
+            hscenv <- dropRnTraceFlags <$> HscMain.getHscEnv
+            uniqSupply <- GHC.liftIO (GHC.mkSplitUniqSupply '0')
+            uniqSupplyRef <- GHC.liftIO $ newIORef uniqSupply
+            let ?hscenv = hscenv
+            let ?uniqSupply = uniqSupplyRef
+            pure x{GHC.hpm_module = onModule <$> GHC.hpm_module x}
 
 
 ---------------------------------------------------------------------
@@ -53,7 +63,7 @@
 var_dot = GHC.mkRdrUnqual $ GHC.mkVarOcc "."
 
 
-onModule :: Module -> Module
+onModule :: PluginEnv => Module -> Module
 onModule x = x { hsmodImports = onImports $ hsmodImports x
                , hsmodDecls = concatMap (onDecl (unLoc <$> hsmodName x)) $ hsmodDecls x
                }
@@ -108,7 +118,7 @@
         vX = GHC.mkRdrUnqual $ GHC.mkVarOcc "x"
 
 
-onDecl :: Maybe GHC.ModuleName -> LHsDecl GhcPs -> [LHsDecl GhcPs]
+onDecl :: PluginEnv => Maybe GHC.ModuleName -> LHsDecl GhcPs -> [LHsDecl GhcPs]
 onDecl modName o@(L _ (GHC.TyClD _ x)) = o :
     [ noL $ InstD noE $ instanceTemplate field (unLoc record) (unbang typ)
     | let fields = nubOrdOn (\(_,_,x,_) -> GHC.occNameFS $ GHC.rdrNameOcc $ unLoc $ rdrNameFieldOcc x) $ getFields modName x
@@ -119,15 +129,13 @@
 unbang (HsBangTy _ _ x) = unLoc x
 unbang x = x
 
-getFields :: Maybe GHC.ModuleName -> TyClDecl GhcPs -> [(LHsType GhcPs, IdP GhcPs, FieldOcc GhcPs, HsType GhcPs)]
+getFields :: PluginEnv => Maybe GHC.ModuleName -> TyClDecl GhcPs -> [(LHsType GhcPs, IdP GhcPs, FieldOcc GhcPs, HsType GhcPs)]
 getFields modName DataDecl{tcdDataDefn=HsDataDefn{..}, ..} = concatMap ctor dd_cons
     where
-        ctor (L _ ConDeclH98{con_args=RecCon (L _ fields),con_name=L _ name}) = concatMap (field name) fields
-        ctor (L _ ConDeclGADT{con_args=RecCon (L _ fields),con_names=names}) = concat [field name fld | L _ name <- names, fld <- fields]
-        ctor _ = []
+        ctor (L _ con) = [(result, name, fld, ty) | (name, fld, ty) <- conClosedFields (defVars tcdTyVars) con]
 
-        field name (L _ ConDeclField{cd_fld_type=L _ ty, ..}) = [(result, name, fld, ty) | L _ fld <- cd_fld_names]
-        field _ _ = error "unknown field declaration in getFields"
+        defVars :: LHsQTyVars GhcPs -> [GHC.RdrName]
+        defVars vars = [v | L _ v <- hsLTyVarLocNames vars]
 
         -- A value of this data declaration will have this type.
         result = foldl (\x y -> noL $ HsAppTy noE x $ hsLTyVarBndrToType y) (noL $ HsTyVar noE GHC.NotPromoted tyName) $ hsq_explicit tcdTyVars
@@ -136,6 +144,25 @@
             _ -> tcdLName
 getFields _ _ = []
 
+-- Extract filed and its type from declaration, omitting fields with existential/higher-kind types.
+conClosedFields :: PluginEnv => [GHC.RdrName] -> ConDecl GhcPs -> [(IdP GhcPs, FieldOcc GhcPs, HsType GhcPs)]
+conClosedFields resultVars = \case
+    ConDeclH98 {con_args = RecCon (L _ args), con_name, con_ex_tvs} ->
+        [ (unLoc con_name, unLoc name, unLoc ty)
+            | ConDeclField {cd_fld_names, cd_fld_type = ty} <- universeBi args,
+                null (freeTyVars' ty \\ resultVars),
+                name <- cd_fld_names
+        ]
+    ConDeclGADT {con_args = RecCon (L _ args), con_res_ty, con_names} ->
+         [ (unLoc con_name, unLoc name, unLoc ty)
+         | ConDeclField {cd_fld_names, cd_fld_type = ty} <- universeBi args,
+             null (freeTyVars ty \\ freeTyVars con_res_ty),
+             name <- cd_fld_names,
+             con_name <- con_names
+         ]
+    _ -> []
+    where
+        freeTyVars' ty = unLoc <$> freeTyVars ty
 
 -- At this point infix expressions have not had associativity/fixity applied, so they are bracketed
 -- a + b + c ==> (a + b) + c
diff --git a/record-dot-preprocessor.cabal b/record-dot-preprocessor.cabal
--- a/record-dot-preprocessor.cabal
+++ b/record-dot-preprocessor.cabal
@@ -1,14 +1,14 @@
 cabal-version:      1.18
 build-type:         Simple
 name:               record-dot-preprocessor
-version:            0.2.13
+version:            0.2.14
 license:            BSD3
 x-license:          BSD-3-Clause OR Apache-2.0
 license-file:       LICENSE
 category:           Development
 author:             Neil Mitchell <ndmitchell@gmail.com>
 maintainer:         Neil Mitchell <ndmitchell@gmail.com>
-copyright:          Neil Mitchell 2018-2021
+copyright:          Neil Mitchell 2018-2022
 synopsis:           Preprocessor to allow record.field syntax
 description:
     In almost every programming language @a.b@ will get the @b@ field from the @a@ data type, and many different data types can have a @b@ field.
diff --git a/test/PluginExample.hs b/test/PluginExample.hs
--- a/test/PluginExample.hs
+++ b/test/PluginExample.hs
@@ -20,6 +20,11 @@
 -- things that are now treated as comments
 {-# OPTIONS_GHC -Werror -Wall -Wno-type-defaults -Wno-partial-type-signatures -Wno-incomplete-record-updates -Wno-unused-top-binds #-}
 {-# LANGUAGE PartialTypeSignatures, GADTs, StandaloneDeriving, KindSignatures #-}
+#if __GLASGOW_HASKELL__ < 808
+-- 8.8+ doesn't need it to be set explicitly
+{-# LANGUAGE ExistentialQuantification #-}
+#endif
+
 module PluginExample where
 #include "../examples/Both.hs"