diff --git a/.gitignore b/.gitignore
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,7 @@
 cabal.config
 .stack-work
 .bash_history
+dist-newstyle
 
 # =========================
 # Operating System Files
diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,23 @@
+0.9.2
+------------------------------------------------
+
+* Supported GHC 9.10 ([#40](https://github.com/fumieval/extensible/pull/40) by [@miguel-negrao](https://github.com/miguel-negrao))
+
+0.9.1
+------------------------------------------------
+
+* Supported GHCs up to 9.8 ([#38](https://github.com/fumieval/extensible/pull/38) by [@kgtkr](https://github.com/kgtkr))
+* Exported `Assoc`, `(>:)`, and `Lookup` from `Data.Extensible.Effect`
+* Added `coinclusionAssoc`, `wrenchAssoc`, and `retrenchAssoc` ([#36](https://github.com/fumieval/extensible/pull/36) by [@At-sushi](https://github.com/At-sushi))
+
+0.9
+------------------------------------------------
+
+* Removed `FieldName`, the relic of the old ages
+    * `(@=)`, `@==`, `@!?` and `lasso` now take `Proxy` instead of `FieldName`. Those who are using `mkField` need to replace the operands with proxies (OverloadedLabels is recommended).
+* Supported aeson 1.x
+* Introduced `IsLabel` flag which toggles the presence of optics `OverloadedLabels`. By disabling it, this package can now coexist with other users of the `IsLabel` class, such as `generic-lens` and `relational-query`.
+
 0.8.3
 ------------------------------------------------
 
diff --git a/extensible.cabal b/extensible.cabal
--- a/extensible.cabal
+++ b/extensible.cabal
@@ -1,6 +1,6 @@
 cabal-version:       2.4
 name:                extensible
-version:             0.8.3
+version:             0.9.2
 synopsis:            Extensible, efficient, optics-friendly data types and effects
 homepage:            https://github.com/fumieval/extensible
 bug-reports:         http://github.com/fumieval/extensible/issues
@@ -12,11 +12,11 @@
 license-file:        LICENSE
 author:              Fumiaki Kinoshita
 maintainer:          Fumiaki Kinoshita <fumiexcel@gmail.com>
-copyright:           Copyright (c) 2017-2021 Fumiaki Kinoshita
+copyright:           Copyright (c) 2017-2022 Fumiaki Kinoshita
 category:            Data, Records
 build-type:          Simple
 stability:           experimental
-Tested-With:         GHC == 8.6.5, GHC == 8.8.4, GHC == 8.10.4, GHC == 9.0.1
+Tested-With:         GHC == 8.10.7, GHC == 9.0.1, GHC == 9.2.1, GHC == 9.10.1
 
 extra-source-files:
   examples/*.hs
@@ -31,11 +31,18 @@
 flag barbies
   default: False
   description: "define instances for barbies"
+  manual: True
 
 flag cassava
   default: True
   description: "define instances for cassava"
+  manual: True
 
+flag IsLabel
+  default: True
+  description: "export the instance of IsLabel making optics (which could conflict with other packages such as generic-lens)"
+  manual: True
+
 library
   exposed-modules:
     Data.Extensible
@@ -73,13 +80,13 @@
     , CPP
     , NoStarIsType
   build-depends:       base >= 4.8 && <5
-    , aeson ^>= 2.0
+    , aeson >= 1.5 && <2.3
     , bytestring
     , comonad
     , constraints
     , deepseq
     , ghc-prim
-    , hashable
+    , hashable >= 1.2 && <1.5
     , incremental >= 0.3.1
     , membership
     , prettyprinter ^>= 1.7
@@ -100,6 +107,8 @@
   if flag(cassava)
     build-depends: cassava
     cpp-options: -DCASSAVA
+  if flag(IsLabel)
+    cpp-options: -DISLABEL
   hs-source-dirs:      src
   ghc-options: -Wall -Wcompat
   default-language:    Haskell2010
diff --git a/src/Data/Extensible.hs b/src/Data/Extensible.hs
--- a/src/Data/Extensible.hs
+++ b/src/Data/Extensible.hs
@@ -32,7 +32,6 @@
   , module Data.Extensible.Dictionary
   , module Data.Extensible.Field
   , module Data.Extensible.Inclusion
-  , module Data.Extensible.Label
   , module Data.Extensible.Match
   , module Data.Extensible.Nullable
   , module Data.Extensible.Product
@@ -51,7 +50,9 @@
 import Data.Extensible.Dictionary
 import Data.Extensible.Field
 import Data.Extensible.Inclusion
-import Data.Extensible.Label
+#ifdef ISLABEL
+import Data.Extensible.Label ()
+#endif
 import Data.Extensible.Match
 import Data.Extensible.Nullable
 import Data.Extensible.Product
diff --git a/src/Data/Extensible/Bits.hs b/src/Data/Extensible/Bits.hs
--- a/src/Data/Extensible/Bits.hs
+++ b/src/Data/Extensible/Bits.hs
@@ -138,7 +138,7 @@
   fromBits = Const . fromBits
   toBits = toBits . getConst
 
-instance (Bits r, FromBits r (h (TargetOf x))) => FromBits r (Field h x) where
+instance (Bits r, KnownNat (BitWidth (h (TargetOf x))), FromBits r (h (TargetOf x))) => FromBits r (Field h x) where
   type BitWidth (Field h x) = BitWidth (h (TargetOf x))
   fromBits = Field . fromBits
   toBits = toBits . getField
diff --git a/src/Data/Extensible/Dictionary.hs b/src/Data/Extensible/Dictionary.hs
--- a/src/Data/Extensible/Dictionary.hs
+++ b/src/Data/Extensible/Dictionary.hs
@@ -3,7 +3,7 @@
 {-# LANGUAGE TypeFamilies, ScopedTypeVariables #-}
 {-# LANGUAGE UndecidableInstances, MultiParamTypeClasses #-}
 {-# LANGUAGE UndecidableSuperClasses #-}
-{-# LANGUAGE TypeInType #-}
+{-# LANGUAGE PolyKinds #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE InstanceSigs #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
@@ -35,8 +35,13 @@
 import Data.Extensible.Nullable
 import Data.Constraint
 import Data.Extensible.Struct
+import Data.Extensible.Wrapper
 import Data.Hashable
+#if MIN_VERSION_aeson(2,0,0)
 import qualified Data.Aeson.KeyMap as KM
+#else
+import qualified Data.HashMap.Strict as KM
+#endif
 import Data.Functor.Compose
 import qualified Data.HashMap.Strict as HM
 import Data.Incremental
@@ -52,6 +57,7 @@
 import qualified Language.Haskell.TH.Syntax as TH
 #endif
 import Language.Haskell.TH hiding (Type)
+import GHC.Records
 import GHC.TypeLits
 import Test.QuickCheck.Arbitrary
 import Test.QuickCheck.Gen
@@ -105,7 +111,7 @@
   mappend = (<>)
   {-# INLINE mappend #-}
 
-instance WrapForall Hashable h xs => Hashable (xs :& h) where
+instance (WrapForall Eq h xs, WrapForall Hashable h xs) => Hashable (xs :& h) where
   hashWithSalt = hfoldlWithIndexFor (Proxy :: Proxy (Instance1 Hashable h))
     (const hashWithSalt)
   {-# INLINE hashWithSalt #-}
@@ -261,7 +267,7 @@
   rnf (EmbedAt i h) = views (pieceAt i) (\(Compose Dict) -> rnf h) (library :: xs :& Compose Dict (Instance1 NFData h))
   {-# INLINE rnf #-}
 
-instance WrapForall Hashable h xs => Hashable (xs :/ h) where
+instance (WrapForall Eq h xs, WrapForall Hashable h xs) => Hashable (xs :/ h) where
   hashWithSalt s (EmbedAt i h) = views (pieceAt i)
     (\(Compose Dict) -> s `hashWithSalt` i `hashWithSalt` h)
     (library :: xs :& Compose Dict (Instance1 Hashable h))
@@ -345,3 +351,6 @@
       check t
         | getAny $ hfoldMap (Any . isJust . unwrapDelta) t = Just t
         | otherwise = Nothing
+
+instance (Lookup xs k v, Wrapper h, Repr h v ~ a) => HasField k (RecordOf h xs) a where
+  getField = unwrap . hlookup (association :: Membership xs (k >: v))
diff --git a/src/Data/Extensible/Field.hs b/src/Data/Extensible/Field.hs
--- a/src/Data/Extensible/Field.hs
+++ b/src/Data/Extensible/Field.hs
@@ -4,7 +4,8 @@
 {-# LANGUAGE ScopedTypeVariables, TypeFamilies #-}
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE TemplateHaskell #-}
-{-# LANGUAGE UndecidableSuperClasses, TypeInType #-}
+{-# LANGUAGE UndecidableSuperClasses #-}
+{-# LANGUAGE PolyKinds #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Extensible.Field
@@ -22,7 +23,7 @@
   , (@:>)
   , (@==)
   , FieldOptic
-  , FieldName
+  , xlb
   , liftField
   , liftField2
   -- * Records and variants
@@ -43,10 +44,6 @@
   , KeyIs
   , TargetIs
   , KeyTargetAre
-  -- * Internal
-  , LabelPhantom
-  , Labelling
-  , Inextensible
   ) where
 import Control.DeepSeq (NFData)
 import qualified Data.Aeson as J
@@ -72,6 +69,7 @@
 import qualified Data.Vector.Generic.Mutable as M
 import qualified Data.Vector.Unboxed as U
 import Foreign.Storable (Storable)
+import GHC.OverloadedLabels
 import GHC.Generics (Generic)
 import GHC.TypeLits hiding (Nat)
 import Language.Haskell.TH.Lift
@@ -241,30 +239,15 @@
   (Extensible f p t
   , ExtensibleConstr t xs (Field h) (k ':> v)
   , Lookup xs k v
-  , Labelling k p
   , Wrapper h)
   => Optic' p f (t xs (Field h)) (Repr h v)
 
--- | The trivial inextensible data type
-data Inextensible (xs :: [k]) (h :: k -> Type)
-
-instance (Functor f, Profunctor p) => Extensible f p Inextensible where
-  pieceAt _ _ = error "Impossible"
-
--- | When you see this type as an argument, it expects a 'FieldLens'.
--- This type is used to resolve the name of the field internally.
-type FieldName k = Optic' (LabelPhantom k) Proxy (Inextensible '[k ':> ()] (Field Proxy)) ()
-
--- | Signifies a field name internally
-type family Labelling s p :: Constraint where
-  Labelling s (LabelPhantom t) = s ~ t
-  Labelling s p = ()
-
--- | A ghostly type which spells the field name
-data LabelPhantom s a b
+instance k ~ l => IsLabel k (Proxy l) where
+  fromLabel = Proxy
 
-instance Profunctor (LabelPhantom s) where
-  dimap _ _ _ = error "Impossible"
+-- | Specialised version of 'itemAssoc'. Stands for "eXtensible LaBel"
+xlb :: Proxy k -> FieldOptic k
+xlb t = itemAssoc t
 
 -- | Annotate a value by the field name.
 --
@@ -274,7 +257,7 @@
 --   <: #str \@= "foo"
 --   <: nil
 -- @
-(@=) :: Wrapper h => FieldName k -> Repr h v -> Field h (k ':> v)
+(@=) :: Wrapper h => Proxy k -> Repr h v -> Field h (k ':> v)
 (@=) _ = Field #. review _Wrapper
 {-# INLINE (@=) #-}
 infix 1 @=
@@ -288,18 +271,18 @@
 --   <: #str \<\@=\> getLine
 --   <: nil
 -- @
-(<@=>) :: (Functor f, Wrapper h) => FieldName k -> f (Repr h v) -> Compose f (Field h) (k ':> v)
+(<@=>) :: (Functor f, Wrapper h) => Proxy k -> f (Repr h v) -> Compose f (Field h) (k ':> v)
 (<@=>) k = comp (k @=)
 {-# INLINE (<@=>) #-}
 infix 1 <@=>
 
 -- | Annotate a value by the field name without 'Wrapper'.
-(@:>) :: FieldName k -> h v -> Field h (k ':> v)
+(@:>) :: Proxy k -> h v -> Field h (k ':> v)
 (@:>) _ = Field
 infix 1 @:>
 
 -- | Kind-monomorphic, unwrapped version of '@='
-(@==) :: FieldName (k :: Symbol) -> v -> Field Identity (k ':> v)
+(@==) :: Proxy (k :: Symbol) -> v -> Field Identity (k ':> v)
 (@==) = (@=)
 {-# INLINE (@==) #-}
 infix 1 @==
diff --git a/src/Data/Extensible/Label.hs b/src/Data/Extensible/Label.hs
--- a/src/Data/Extensible/Label.hs
+++ b/src/Data/Extensible/Label.hs
@@ -10,26 +10,16 @@
 --
 -- Experimental API for OverloadedLabels. GHC 8.0+ only
 -----------------------------------------------------------------------------
-module Data.Extensible.Label where
+module Data.Extensible.Label () where
 
 import Data.Extensible.Class
 import Data.Extensible.Field
-import Data.Extensible.Product (hlookup)
 import Data.Proxy
 import GHC.OverloadedLabels
-import GHC.Records
 import Data.Extensible.Wrapper
 
-instance k ~ l => IsLabel k (Proxy l) where
-  fromLabel = Proxy
-
--- | Specialised version of 'itemAssoc'. Stands for "eXtensible LaBel"
-xlb :: Proxy k -> FieldOptic k
-xlb t = itemAssoc t
-
 instance (Extensible f p e
   , Lookup xs k v
-  , Labelling k p
   , Wrapper h
   , ExtensibleConstr e xs (Field h) (k ':> v)
   , rep ~ Repr h v
@@ -39,6 +29,3 @@
   )
   => IsLabel k (p rep (f rep') -> p s (f t)) where
   fromLabel = itemAssoc (Proxy :: Proxy k)
-
-instance (Lookup xs k v, Wrapper h, Repr h v ~ a) => HasField k (RecordOf h xs) a where
-  getField = unwrap . hlookup (association :: Membership xs (k >: v))
diff --git a/src/Data/Extensible/Nullable.hs b/src/Data/Extensible/Nullable.hs
--- a/src/Data/Extensible/Nullable.hs
+++ b/src/Data/Extensible/Nullable.hs
@@ -15,7 +15,10 @@
   , retrench
   , Nullable(..)
   , mapNullable
-  , fromNullable) where
+  , fromNullable
+  , coinclusionAssoc
+  , wrenchAssoc
+  , retrenchAssoc) where
 
 import Control.DeepSeq (NFData)
 import Data.Extensible.Class
@@ -80,3 +83,22 @@
 fromNullable :: h x -> Nullable h x -> h x
 fromNullable def = fromMaybe def . getNullable
 {-# INLINE fromNullable #-}
+
+------------------------------------------------------------------
+
+-- | The inverse of 'inclusionAssoc'.
+coinclusionAssoc :: (IncludeAssoc ys xs, Generate ys) => ys :& Nullable (Membership xs)
+coinclusionAssoc = S.hfrozen $ do
+  s <- S.newRepeat $ Nullable Nothing
+  hfoldrWithIndex
+    (\i m cont -> S.set s m (Nullable $ Just i) >> cont) (return s) inclusionAssoc
+
+-- | Extend a product and fill missing fields by 'Null'.
+wrenchAssoc :: (Generate ys, IncludeAssoc ys xs) => xs :& h -> ys :& Nullable h
+wrenchAssoc xs = mapNullable (flip hlookup xs) `hmap` coinclusionAssoc
+{-# INLINE wrenchAssoc #-}
+
+-- | Narrow the range of the sum, if possible.
+retrenchAssoc :: (Generate ys, IncludeAssoc ys xs) => ys :/ h -> Nullable ((:/) xs) h
+retrenchAssoc (EmbedAt i h) = views (pieceAt i) (mapNullable (`EmbedAt`h)) coinclusionAssoc
+{-# INLINE retrenchAssoc #-}
diff --git a/src/Data/Extensible/TH.hs b/src/Data/Extensible/TH.hs
--- a/src/Data/Extensible/TH.hs
+++ b/src/Data/Extensible/TH.hs
@@ -29,8 +29,10 @@
 -- @
 --
 mkField :: String -> DecsQ
-mkField str = fmap concat $ forM (words str) $ \s@(x:xs) ->
-  let name = mkName $ if isLower x then x : xs else '_' : x : xs
+mkField str = fmap concat $ forM (words str) $ \s ->
+  let name = mkName $ case s of
+        x : xs -> if isLower x then x : xs else '_' : x : xs
+        _ -> error "Impossible"
   in mkFieldAs name s
 
 -- | @'mkFieldAs' (mkName "foo") "bar"@ defines a field for "bar" as @foo@.
diff --git a/src/Data/Extensible/Tangle.hs b/src/Data/Extensible/Tangle.hs
--- a/src/Data/Extensible/Tangle.hs
+++ b/src/Data/Extensible/Tangle.hs
@@ -23,11 +23,11 @@
 import Control.Monad.Trans.Class
 import Data.Functor.Compose
 import Data.Extensible.Class
-import Data.Extensible.Field
 import Data.Extensible.Product
 import Data.Extensible.Internal.Rig
 import Data.Extensible.Nullable
 import Data.Extensible.Wrapper
+import Data.Proxy
 
 -- | @'TangleT' h xs m@ is the monad of computations that may depend on the elements in 'xs'.
 newtype TangleT xs h m a = TangleT
@@ -46,7 +46,7 @@
 
 -- | Hitch an element associated to the 'FieldName' through a wrapper.
 lasso :: forall k v m h xs. (Monad m, Lookup xs k v, Wrapper h)
-  => FieldName k -> TangleT xs h m (Repr h (k ':> v))
+  => Proxy k -> TangleT xs h m (Repr h (k ':> v))
 lasso _ = view _Wrapper <$> hitchAt (association :: Membership xs (k ':> v))
 {-# INLINE lasso #-}