diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2022-09-17 Sergey Vinokurov <serg.foo@gmail.com>
+
+	* 0.7.2.2: Compatibility with GHC 9.4
+
+2021-01-20 Sergey Vinokurov <serg.foo@gmail.com>
+
+	* 0.7.2.1: Update cabal version
+
 2021-01-18 Sergey Vinokurov <serg.foo@gmail.com>
 
 	* 0.7.2: Add compatibility with GHC 9, switch to tasty for tests,
diff --git a/syb.cabal b/syb.cabal
--- a/syb.cabal
+++ b/syb.cabal
@@ -1,5 +1,5 @@
 name:                 syb
-version:              0.7.2.1
+version:              0.7.2.2
 license:              BSD3
 license-file:         LICENSE
 author:               Ralf Lammel, Simon Peyton Jones, Jose Pedro Magalhaes
diff --git a/tests/Bits.hs b/tests/Bits.hs
--- a/tests/Bits.hs
+++ b/tests/Bits.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module Bits (tests) where
 
@@ -134,7 +134,7 @@
   fmap  = liftM
 
 instance Applicative ReadB where
-  pure  = return
+  pure a = ReadB (\bs -> (Just a, bs))
   (<*>) = ap
 
 instance Alternative ReadB where
@@ -143,7 +143,7 @@
 
 -- It's a monad.
 instance Monad ReadB where
-  return a = ReadB (\bs -> (Just a, bs))
+  return = pure
   (ReadB c) >>= f = ReadB (\bs -> case c bs of
                              (Just a, bs')  -> unReadB (f a) bs'
                              (Nothing, bs') -> (Nothing, bs')
diff --git a/tests/Builders.hs b/tests/Builders.hs
--- a/tests/Builders.hs
+++ b/tests/Builders.hs
@@ -1,5 +1,3 @@
-{-# OPTIONS -fglasgow-exts #-}
-
 module Builders (tests) where
 
 -- Testing Data.Generics.Builders functionality
diff --git a/tests/CompanyDatatypes.hs b/tests/CompanyDatatypes.hs
--- a/tests/CompanyDatatypes.hs
+++ b/tests/CompanyDatatypes.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module CompanyDatatypes where
 
diff --git a/tests/Datatype.hs b/tests/Datatype.hs
--- a/tests/Datatype.hs
+++ b/tests/Datatype.hs
@@ -1,5 +1,5 @@
-{-# LANGUAGE CPP #-}
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE CPP                #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 -- These are simple tests to observe (data)type representations.
 module Datatype  where
@@ -34,22 +34,25 @@
             ))))))
        @?= output
 
-#if __GLASGOW_HASKELL__ >= 709
+# if __GLASGOW_HASKELL__ >= 904
+-- In GHC 9.4 module name is included
+output = "(MyDataType Int,(DataType {tycon = \"Datatype.MyDataType\", datarep = AlgRep [MyDataType]},(\"\",(\"MyDataType\",(\"Datatype\",\"MyDataType\")))))"
+# elif __GLASGOW_HASKELL__ >= 709
 -- In GHC 7.10 module name is stripped from DataType
 output = "(MyDataType Int,(DataType {tycon = \"MyDataType\", datarep = AlgRep [MyDataType]},(\"\",(\"MyDataType\",(\"\",\"MyDataType\")))))"
-#else
+# else
 output = "(MyDataType Int,(DataType {tycon = \"Datatype.MyDataType\", datarep = AlgRep [MyDataType]},(\"\",(\"MyDataType\",(\"Datatype\",\"MyDataType\")))))"
-#endif
+# endif
 
 #else
 
 tests = show ( myTypeRep, myDataType )
         @?= output
 
-#if __GLASGOW_HASKELL__ >= 701
+# if __GLASGOW_HASKELL__ >= 701
 output = "(MyDataType Int,DataType {tycon = \"Datatype.MyDataType\", datarep = AlgRep [MyDataType]})"
-#else
+# else
 output = "(Datatype.MyDataType Int,DataType {tycon = \"Datatype.MyDataType\", datarep = AlgRep [MyDataType]})"
-#endif
+# endif
 
 #endif
diff --git a/tests/Encode.hs b/tests/Encode.hs
--- a/tests/Encode.hs
+++ b/tests/Encode.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE EmptyDataDecls     #-}
 
 -- A bit more test code for the 2nd boilerplate paper.
 -- These are downscaled versions of library functionality or real test cases.
@@ -67,11 +68,10 @@
 instance Functor EncM where
   fmap  = liftM
 instance Applicative EncM where
-  pure  = return
+  pure  = undefined
   (<*>) = ap
-instance Monad EncM
- where
-  return  = undefined
+instance Monad EncM where
+  return  = pure
   c >>= f = undefined
 
 runEnc  :: EncM () -> [Bit]
@@ -84,5 +84,5 @@
 data2bits'' t = runEnc (emit t)
 
 emit :: Data a => a -> EncM ()
-emit t = do { emitCon (dataTypeOf t) (toConstr t) 
+emit t = do { emitCon (dataTypeOf t) (toConstr t)
             ; sequence_ (gmapQ emit t) }
diff --git a/tests/Ext.hs b/tests/Ext.hs
--- a/tests/Ext.hs
+++ b/tests/Ext.hs
@@ -1,5 +1,3 @@
-{-# OPTIONS -fglasgow-exts #-}
-
 module Ext () where
 
 -- There were typos in these definitions in the ICFP 2004 paper.
@@ -10,14 +8,14 @@
   = case gcast (Q spec_fn) of
       Just (Q spec_fn') -> spec_fn' arg
       Nothing           -> fn       arg
-                                                                                
+
 newtype Q r a = Q (a -> r)
-                                                                                
+
 extT fn spec_fn arg
   = case gcast (T spec_fn) of
       Just (T spec_fn') -> spec_fn' arg
       Nothing           -> fn       arg
-                                                                                
+
 newtype T a = T (a -> a)
 
 extM :: (Typeable a, Typeable b)
diff --git a/tests/Ext1.hs b/tests/Ext1.hs
--- a/tests/Ext1.hs
+++ b/tests/Ext1.hs
@@ -1,5 +1,6 @@
-{-# OPTIONS -fglasgow-exts #-}
-{-# LANGUAGE CPP #-}
+{-# LANGUAGE CPP        #-}
+{-# LANGUAGE MagicHash  #-}
+{-# LANGUAGE RankNTypes #-}
 
 module Ext1 (tests) where
 
diff --git a/tests/FreeNames.hs b/tests/FreeNames.hs
--- a/tests/FreeNames.hs
+++ b/tests/FreeNames.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module FreeNames (tests) where
 
diff --git a/tests/GEq.hs b/tests/GEq.hs
--- a/tests/GEq.hs
+++ b/tests/GEq.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module GEq (tests) where
 
diff --git a/tests/GMapQAssoc.hs b/tests/GMapQAssoc.hs
--- a/tests/GMapQAssoc.hs
+++ b/tests/GMapQAssoc.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE RankNTypes         #-}
 
 module GMapQAssoc (tests) where
 
diff --git a/tests/GRead.hs b/tests/GRead.hs
--- a/tests/GRead.hs
+++ b/tests/GRead.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module GRead (tests) where
 
diff --git a/tests/GRead2.hs b/tests/GRead2.hs
--- a/tests/GRead2.hs
+++ b/tests/GRead2.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable  #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 module GRead2 () where
 
@@ -24,17 +25,17 @@
     fmap  = liftM
 
 instance Applicative DecM where
-    pure  = return
+    pure a = D (\s -> Just (s,a))
     (<*>) = ap
 
 instance Monad DecM where
-    return a = D (\s -> Just (s,a))
+    return = pure
     (D m) >>= k = D (\s ->
       case m s of
         Nothing -> Nothing
         Just (s1,a) -> let D n = k a
                         in n s1)
-        
+
 runDec :: String -> DecM a -> Maybe a
 runDec input (D m) = do (_,x) <- m input
                         return x
diff --git a/tests/GShow.hs b/tests/GShow.hs
--- a/tests/GShow.hs
+++ b/tests/GShow.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module GShow (tests) where
 
diff --git a/tests/GShow2.hs b/tests/GShow2.hs
--- a/tests/GShow2.hs
+++ b/tests/GShow2.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module GShow2 (tests) where
 
diff --git a/tests/GZip.hs b/tests/GZip.hs
--- a/tests/GZip.hs
+++ b/tests/GZip.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable  #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 module GZip (tests) where
 
diff --git a/tests/GenUpTo.hs b/tests/GenUpTo.hs
--- a/tests/GenUpTo.hs
+++ b/tests/GenUpTo.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module GenUpTo (tests) where
 
diff --git a/tests/GetC.hs b/tests/GetC.hs
--- a/tests/GetC.hs
+++ b/tests/GetC.hs
@@ -1,6 +1,17 @@
-{-# OPTIONS -fglasgow-exts #-}
-{-# LANGUAGE OverlappingInstances, UndecidableInstances #-}
+{-# LANGUAGE DeriveDataTypeable        #-}
+{-# LANGUAGE ExistentialQuantification #-}
+{-# LANGUAGE FlexibleContexts          #-}
+{-# LANGUAGE FlexibleInstances         #-}
+{-# LANGUAGE FunctionalDependencies    #-}
+{-# LANGUAGE MultiParamTypeClasses     #-}
+{-# LANGUAGE ScopedTypeVariables       #-}
+{-# LANGUAGE UndecidableInstances      #-}
 
+{-# LANGUAGE CPP #-}
+# if __GLASGOW_HASKELL__ <= 708
+{-# LANGUAGE OverlappingInstances      #-}
+#endif
+
 module GetC (tests) where
 
 import Test.Tasty.HUnit
@@ -73,8 +84,8 @@
 --
 
 class GetT f t | f -> t -- FD is optional
-instance GetT g t => GetT (x -> g) t
-instance TypeUnify t t' => GetT t t'
+instance  GetT g t => GetT (x -> g) t
+instance {-# OVERLAPPABLE #-} TypeUnify t t' => GetT t t'
 
 
 --
@@ -94,7 +105,7 @@
          (x::x) <- unExTypeable h
          getC (f x) t
 
-instance Data t => GetC t
+instance {-# OVERLAPPABLE #-} Data t => GetC t
  where
   getC y []    = Just $ toConstr y
   getC _ (_:_) = Nothing
diff --git a/tests/HList.hs b/tests/HList.hs
--- a/tests/HList.hs
+++ b/tests/HList.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE ExistentialQuantification #-}
 
 module HList (tests) where
 
diff --git a/tests/HOPat.hs b/tests/HOPat.hs
--- a/tests/HOPat.hs
+++ b/tests/HOPat.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE ExplicitForAll     #-}
 
 module HOPat (tests) where
 
diff --git a/tests/Labels.hs b/tests/Labels.hs
--- a/tests/Labels.hs
+++ b/tests/Labels.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module Labels (tests) where
 
diff --git a/tests/LocalQuantors.hs b/tests/LocalQuantors.hs
--- a/tests/LocalQuantors.hs
+++ b/tests/LocalQuantors.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE RankNTypes         #-}
 
 module LocalQuantors () where
 
@@ -12,7 +13,7 @@
 
 instance Data Test
   where
-    gfoldl _ z x = z x -- folding without descent 
+    gfoldl _ z x = z x -- folding without descent
     toConstr (Test _) = testConstr
     gunfold _ _ = error "gunfold"
     dataTypeOf _ = testDataType
diff --git a/tests/NestedDatatypes.hs b/tests/NestedDatatypes.hs
--- a/tests/NestedDatatypes.hs
+++ b/tests/NestedDatatypes.hs
@@ -1,6 +1,7 @@
-{-# OPTIONS -fglasgow-exts #-}
-{-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE DeriveDataTypeable   #-}
+{-# LANGUAGE FlexibleContexts     #-}
+{-# LANGUAGE MonoLocalBinds       #-}
+{-# LANGUAGE UndecidableInstances #-}
 
 module NestedDatatypes () where
 
@@ -19,7 +20,7 @@
 import Data.Dynamic
 import Data.Generics
 
- 
+
 -- A nested datatype
 data Nest a = Box a | Wrap (Nest [a]) deriving Typeable
 
diff --git a/tests/Newtype.hs b/tests/Newtype.hs
--- a/tests/Newtype.hs
+++ b/tests/Newtype.hs
@@ -1,5 +1,5 @@
-{-# LANGUAGE CPP #-}
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE CPP                #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module Newtype (tests) where
 
diff --git a/tests/Paradise.hs b/tests/Paradise.hs
--- a/tests/Paradise.hs
+++ b/tests/Paradise.hs
@@ -1,5 +1,3 @@
-{-# OPTIONS -fglasgow-exts #-}
-
 module Paradise (tests) where
 
 {-
diff --git a/tests/Perm.hs b/tests/Perm.hs
--- a/tests/Perm.hs
+++ b/tests/Perm.hs
@@ -1,4 +1,6 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable  #-}
+{-# LANGUAGE RankNTypes          #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 module Perm (tests) where
 
@@ -49,7 +51,7 @@
   fmap  = liftM
 
 instance Applicative ReadT where
-  pure  = return
+  pure x = ReadT (\y -> Just (y,x))
   (<*>) = ap
 
 instance Alternative ReadT where
@@ -58,7 +60,7 @@
 
 -- ReadT is a monad!
 instance Monad ReadT where
-  return x = ReadT (\y -> Just (y,x))
+  return   = pure
   c >>= f  = ReadT (\x -> case unReadT c x of
                             Nothing -> Nothing
                             Just (x', a) -> unReadT (f a) x'
diff --git a/tests/Polymatch.hs b/tests/Polymatch.hs
--- a/tests/Polymatch.hs
+++ b/tests/Polymatch.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable        #-}
+{-# LANGUAGE ExistentialQuantification #-}
 
 module Polymatch () where
 
@@ -13,7 +14,7 @@
 data Kid  = forall k. Typeable k => Kid k
 
 
--- Build term from a list of kids and the constructor 
+-- Build term from a list of kids and the constructor
 fromConstrL :: Data a => Kids -> Constr -> Maybe a
 fromConstrL l = unIDL . gunfold k z
  where
@@ -42,7 +43,7 @@
 
 f g (Right a)    = Right $ g a       -- conversion really needed
 -- f g (Left  s) = Left s            -- unappreciated conversion
--- f g s         = s                 -- doesn't typecheck 
+-- f g s         = s                 -- doesn't typecheck
 -- f g s         = deep_rebuild s    -- too expensive
 f g s            = just (shallow_rebuild s) -- perhaps this is Ok?
 
@@ -58,7 +59,7 @@
 
 -- For the record: it's possible.
 shallow_rebuild :: (Data a, Data b) => a -> Maybe b
-shallow_rebuild a = b 
+shallow_rebuild a = b
  where
   b      = fromConstrL (kids a) constr
   constr = indexConstr (dataTypeOf b) (constrIndex (toConstr a))
diff --git a/tests/Reify.hs b/tests/Reify.hs
--- a/tests/Reify.hs
+++ b/tests/Reify.hs
@@ -1,5 +1,8 @@
-{-# OPTIONS -fglasgow-exts #-}
 
+{-# LANGUAGE DeriveDataTypeable  #-}
+{-# LANGUAGE RankNTypes          #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+
 module Reify (tests) where
 
 {-
@@ -92,7 +95,7 @@
 -- Generic type functions,
 -- i.e., functions mapping types to values
 --
-type GTypeFun r  = forall a. Data a => TypeFun a r
+type GTypeFun r = forall a. Data a => TypeFun a r
 
 
 
diff --git a/tests/Strings.hs b/tests/Strings.hs
--- a/tests/Strings.hs
+++ b/tests/Strings.hs
@@ -1,5 +1,3 @@
-{-# OPTIONS -fglasgow-exts #-}
-
 module Strings (tests) where
 
 {-
diff --git a/tests/Tree.hs b/tests/Tree.hs
--- a/tests/Tree.hs
+++ b/tests/Tree.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 module Tree (tests) where
 
@@ -34,13 +34,13 @@
     gdefault (Node x ts) = res
       where
 
-	-- a helper for type capture
+        -- a helper for type capture
         res  = maybe Nothing (kids . fromConstr) con
 
-	-- the type to constructed
+        -- the type to constructed
         ta   = fromJust res
 
-	-- construct constructor
+        -- construct constructor
         con  = readConstr (dataTypeOf ta) x
 
         -- recursion per kid with accumulation
diff --git a/tests/Twin.hs b/tests/Twin.hs
--- a/tests/Twin.hs
+++ b/tests/Twin.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE ExistentialQuantification #-}
+{-# LANGUAGE RankNTypes                #-}
 
 module Twin (tests) where
 
diff --git a/tests/Typecase1.hs b/tests/Typecase1.hs
--- a/tests/Typecase1.hs
+++ b/tests/Typecase1.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module Typecase1 (tests) where
 
diff --git a/tests/Typecase2.hs b/tests/Typecase2.hs
--- a/tests/Typecase2.hs
+++ b/tests/Typecase2.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module Typecase2 (tests) where
 
diff --git a/tests/Where.hs b/tests/Where.hs
--- a/tests/Where.hs
+++ b/tests/Where.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module Where (tests) where
 
diff --git a/tests/XML.hs b/tests/XML.hs
--- a/tests/XML.hs
+++ b/tests/XML.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fglasgow-exts #-}
+{-# LANGUAGE DeriveDataTypeable  #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 module XML (tests) where
 
@@ -162,7 +163,7 @@
   fmap  = liftM
 
 instance Applicative ReadX where
-  pure  = return
+  pure x = ReadX (\y -> Just (y,x))
   (<*>) = ap
 
 instance Alternative ReadX where
@@ -171,7 +172,7 @@
 
 -- ReadX is a monad!
 instance Monad ReadX where
-  return x = ReadX (\y -> Just (y,x))
+  return = pure
   c >>= f  = ReadX (\x -> case unReadX c x of
                             Nothing -> Nothing
                             Just (x', a) -> unReadX (f a) x'