diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,7 @@
+## [0.7] - 2024-12-15
+- update for witness-0.7
+- fix for GHC 9.8, 9.10
+
 ## [0.6] - 2022-05-10
 - update for witness-0.6
 - move module hierarchy
diff --git a/open-witness.cabal b/open-witness.cabal
--- a/open-witness.cabal
+++ b/open-witness.cabal
@@ -1,25 +1,32 @@
 cabal-version: 2.2
 
--- This file has been generated from package.yaml by hpack version 0.34.4.
+-- This file has been generated from package.yaml by hpack version 0.37.0.
 --
 -- see: https://github.com/sol/hpack
 
 name:           open-witness
-version:        0.6
+version:        0.7
 synopsis:       open witnesses
 description:    Open witnesses are witnesses that can witness to any type. However, they cannot be constructed, they can only be generated in the IO monad. See the 2008 draft paper /Witnesses and Open Witnesses/ (<https://semantic.org/wp-content/uploads/Open-Witnesses.pdf>).
 category:       Data
-homepage:       https://github.com/AshleyYakeley/open-witness
+homepage:       https://github.com/AshleyYakeley/open-witness#readme
 bug-reports:    https://github.com/AshleyYakeley/open-witness/issues
 author:         Ashley Yakeley
 maintainer:     <ashley@semantic.org>
-copyright:      (c) 2017-2022 Ashley Yakeley
+copyright:      (c) 2017-2024 Ashley Yakeley
 license:        BSD-2-Clause
 license-file:   LICENSE
 build-type:     Simple
-extra-source-files:
+tested-with:
+    GHC == 9.8.4
+  , GHC == 9.10.1
+extra-doc-files:
     changelog.md
 
+source-repository head
+  type: git
+  location: https://github.com/AshleyYakeley/open-witness
+
 library
   exposed-modules:
       Data.Type.OpenWitness
@@ -35,57 +42,39 @@
   default-extensions:
       AllowAmbiguousTypes
       Arrows
-      ConstraintKinds
       DataKinds
       DefaultSignatures
-      EmptyCase
-      EmptyDataDecls
-      ExistentialQuantification
-      FlexibleContexts
-      FlexibleInstances
-      ForeignFunctionInterface
+      DerivingStrategies
       FunctionalDependencies
-      GADTs
-      GeneralizedNewtypeDeriving
       ImplicitParams
       NoImplicitPrelude
-      InstanceSigs
-      KindSignatures
       LambdaCase
-      MultiParamTypeClasses
       OverloadedLabels
       OverloadedStrings
       PartialTypeSignatures
-      PatternGuards
       PatternSynonyms
-      PolyKinds
-      RankNTypes
+      QuantifiedConstraints
       RecordWildCards
       RecursiveDo
       RoleAnnotations
-      ScopedTypeVariables
-      StandaloneDeriving
       NoStarIsType
       TemplateHaskell
-      TypeApplications
+      TypeAbstractions
       TypeFamilies
       TypeFamilyDependencies
-      TypeInType
-      TypeOperators
-      TypeSynonymInstances
       UndecidableInstances
       UndecidableSuperClasses
       ViewPatterns
-  ghc-options: -Wall -Wincomplete-uni-patterns -Wincomplete-record-updates -Wcompat -Wnoncanonical-monad-instances
+  ghc-options: -Weverything -Wno-missing-import-lists -Wno-missing-export-lists -Wno-unsafe -Wno-missing-safe-haskell-mode -Wno-missing-kind-signatures -Wno-partial-type-signatures -Wno-missing-role-annotations -Wno-monomorphism-restriction -Wno-missing-local-signatures -Wno-partial-fields -Wno-all-missed-specialisations -Wno-missed-specialisations
   build-depends:
-      base >=4.15 && <5
-    , constraints >=0.13
+      base >=4.19 && <5
+    , constraints >=0.14
     , hashable >=1.3
     , random >=1.2
     , template-haskell >=2.17
     , transformers >=0.5
-    , witness >=0.6
-  default-language: Haskell2010
+    , witness >=0.7
+  default-language: GHC2021
 
 test-suite tests
   type: exitcode-stdio-1.0
@@ -95,19 +84,36 @@
   hs-source-dirs:
       test
   default-extensions:
-      RankNTypes
-      EmptyDataDecls
-      GeneralizedNewtypeDeriving
-      ScopedTypeVariables
-      GADTs
-      FlexibleContexts
-      MultiParamTypeClasses
+      AllowAmbiguousTypes
+      Arrows
+      DataKinds
+      DefaultSignatures
+      DerivingStrategies
+      FunctionalDependencies
+      ImplicitParams
+      NoImplicitPrelude
+      LambdaCase
+      OverloadedLabels
+      OverloadedStrings
+      PartialTypeSignatures
+      PatternSynonyms
+      QuantifiedConstraints
+      RecordWildCards
+      RecursiveDo
+      RoleAnnotations
+      NoStarIsType
       TemplateHaskell
+      TypeAbstractions
+      TypeFamilies
+      TypeFamilyDependencies
+      UndecidableInstances
+      UndecidableSuperClasses
+      ViewPatterns
+  ghc-options: -Weverything -Wno-missing-import-lists -Wno-missing-export-lists -Wno-unsafe -Wno-missing-safe-haskell-mode -Wno-missing-kind-signatures -Wno-partial-type-signatures -Wno-missing-role-annotations -Wno-monomorphism-restriction -Wno-missing-local-signatures -Wno-partial-fields -Wno-all-missed-specialisations -Wno-missed-specialisations
   build-depends:
-      base >=4.15 && <5
-    , mtl
+      base >=4.19 && <5
     , open-witness
     , tasty
     , tasty-hunit
     , witness
-  default-language: Haskell2010
+  default-language: GHC2021
diff --git a/src/Data/Type/OpenWitness.hs b/src/Data/Type/OpenWitness.hs
--- a/src/Data/Type/OpenWitness.hs
+++ b/src/Data/Type/OpenWitness.hs
@@ -24,7 +24,7 @@
 import Data.Traversable
 import Data.Type.Witness
 import Language.Haskell.TH hiding (Type)
-import qualified Language.Haskell.TH
+import Language.Haskell.TH qualified
 import Prelude
 import System.IO.Unsafe (unsafePerformIO)
 import System.Random
@@ -67,6 +67,7 @@
 data RealWorld
 
 -- | An 'OpenWitness' for 'IO'.
+type IOWitness :: forall k. k -> Type
 type IOWitness = OpenWitness RealWorld
 
 ioWitnessSource :: MVar Int64
@@ -84,9 +85,10 @@
 
 -- | A runnable monad in which 'OpenWitness' values can be generated.
 -- The @s@ parameter plays the same role as it does in 'ST', preventing 'OpenWitness' values from one run being used in another.
+type OW :: forall k. k -> Type -> Type
 newtype OW s a =
     MkOW (State OWState a)
-    deriving (Functor, Applicative, Monad, MonadFix)
+    deriving newtype (Functor, Applicative, Monad, MonadFix)
 
 -- | Run an 'OW' computation.
 runOW :: forall a. (forall s. OW s a) -> a
diff --git a/src/Data/Type/OpenWitness/Exception.hs b/src/Data/Type/OpenWitness/Exception.hs
--- a/src/Data/Type/OpenWitness/Exception.hs
+++ b/src/Data/Type/OpenWitness/Exception.hs
@@ -8,11 +8,10 @@
     , catch
     ) where
 
-import qualified Control.Exception as CE (Exception, catch, throw)
+import Control.Exception qualified as CE (Exception, catch, throw)
 import Data.Kind
 import Data.Type.OpenWitness
 import Data.Type.Witness
-import Data.Typeable
 import Language.Haskell.TH hiding (Type)
 import Prelude
 
@@ -25,7 +24,6 @@
 
 newtype ExnException =
     MkExnException (SomeOf Exn)
-    deriving (Typeable)
 
 -- | Template Haskell function to declare 'Exn' exception keys.
 declexn :: TypeQ -> Q Exp
diff --git a/src/Data/Type/OpenWitness/ST.hs b/src/Data/Type/OpenWitness/ST.hs
--- a/src/Data/Type/OpenWitness/ST.hs
+++ b/src/Data/Type/OpenWitness/ST.hs
@@ -21,13 +21,14 @@
 import Control.Monad.Trans.Class
 import Control.Monad.Trans.State
 import Data.Type.OpenWitness
-import Data.Type.Witness.Specific.WitnessMap.Of
+import Data.Type.Witness.Specific.OrderedWitnessMap.Of
 import Prelude
+import Data.Kind
 
-type ST s = StateT (WitnessMapOf (OpenWitness s)) (OW s)
+type ST s = StateT (OrderedWitnessMapOf (OpenWitness s)) (OW s)
 
 stToOW :: ST s a -> OW s a
-stToOW st = evalStateT st emptyWitnessMapOf
+stToOW st = evalStateT st emptyOrderedWitnessMapOf
 
 runST :: (forall s. ST s a) -> a
 runST st = runOW (stToOW st)
@@ -35,27 +36,28 @@
 fixST :: (a -> ST s a) -> ST s a
 fixST = mfix
 
+type STRef :: forall k. Type -> k -> Type
 type STRef s = OpenWitness s
 
 newSTRef :: a -> ST s (STRef s a)
 newSTRef a = do
     wit <- lift newOpenWitnessOW
     dict <- get
-    put (witnessMapOfAdd wit a dict)
+    put (orderedWitnessMapOfAdd wit a dict)
     return wit
 
 readSTRef :: STRef s a -> ST s a
 readSTRef key = do
     dict <- get
-    case witnessMapOfLookup key dict of
+    case orderedWitnessMapOfLookup key dict of
         Just a -> return a
         _ -> error "ref not found"
 
 writeSTRef :: forall s a. STRef s a -> a -> ST s ()
-writeSTRef key newa = modify (witnessMapOfReplace key newa)
+writeSTRef key newa = modify (orderedWitnessMapOfReplace key newa)
 
 modifySTRef :: forall s a. STRef s a -> (a -> a) -> ST s ()
-modifySTRef key amap = modify (witnessMapOfModify key amap)
+modifySTRef key amap = modify (orderedWitnessMapOfModify key amap)
 
 stToIO :: ST RealWorld a -> IO a
 stToIO = owToIO . stToOW
diff --git a/src/Data/Type/OpenWitness/Witnessed.hs b/src/Data/Type/OpenWitness/Witnessed.hs
--- a/src/Data/Type/OpenWitness/Witnessed.hs
+++ b/src/Data/Type/OpenWitness/Witnessed.hs
@@ -10,8 +10,10 @@
 import Data.Type.OpenWitness
 import Data.Type.Witness
 import Prelude
+import Data.Kind
 
-type Witnessed = PairType IOWitness
+type Witnessed :: forall k. (k -> Type) -> k -> Type
+type Witnessed @k = PairType @k IOWitness
 
 unWitnessed :: Witnessed f a -> f a
 unWitnessed (MkPairType _ fa) = fa
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -33,7 +33,7 @@
     = NotCaught
     | IntCaught Int
     | StringCaught String
-    deriving (Eq, Show)
+    deriving stock (Eq, Show)
 
 getCaught :: IO a -> IO Caught
 getCaught f =
@@ -56,7 +56,7 @@
     testGroup
         "test"
         [ testST
-        , testCaught "return" NotCaught $ return "hello"
+        , testCaught "return" NotCaught $ return ("hello" :: String)
         , testCaught "throw intExn 3" (IntCaught 3) $ throw intExn 3
         , testCaught "throw stringExn text" (StringCaught "text") $ throw stringExn "text"
         , testCaught "throw intExn 67" (IntCaught 67) $ throw intExn 67
diff --git a/test/Object.hs b/test/Object.hs
--- a/test/Object.hs
+++ b/test/Object.hs
@@ -2,6 +2,7 @@
 
 import Data.Type.OpenWitness
 import Data.Type.Witness
+import Prelude
 
 data Object s =
     forall a. MkObject (OpenWitness s a)