diff --git a/fastmemo.cabal b/fastmemo.cabal
--- a/fastmemo.cabal
+++ b/fastmemo.cabal
@@ -1,11 +1,11 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.35.0.
+-- This file has been generated from package.yaml by hpack version 0.39.6.
 --
 -- see: https://github.com/sol/hpack
 
 name:           fastmemo
-version:        0.1.1
+version:        0.1.2
 synopsis:       Memoize functions on Generic types
 description:    Please see the README on GitHub at <https://github.com/davidspies/fastmemo#readme>
 category:       Memoization
@@ -32,6 +32,7 @@
       Data.Function.FastMemo.Char
       Data.Function.FastMemo.Class
       Data.Function.FastMemo.Containers
+      Data.Function.FastMemo.DList
       Data.Function.FastMemo.Instances
       Data.Function.FastMemo.Int
       Data.Function.FastMemo.Integer
@@ -46,9 +47,10 @@
       src
   ghc-options: -Wall
   build-depends:
-      base >=4.7 && <4.18
-    , bytestring >=0.10 && <0.12
-    , containers ==0.6.*
+      base >=4.7 && <4.22
+    , bytestring >=0.10 && <0.13
+    , containers >=0.6 && <0.9
+    , dlist
     , utf8-string ==1.0.*
     , vector >=0.12 && <0.14
   default-language: Haskell2010
@@ -64,9 +66,10 @@
   ghc-options: -Wall -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       QuickCheck
-    , base >=4.7 && <4.18
-    , bytestring >=0.10 && <0.12
-    , containers ==0.6.*
+    , base >=4.7 && <4.22
+    , bytestring >=0.10 && <0.13
+    , containers >=0.6 && <0.9
+    , dlist
     , fastmemo
     , utf8-string ==1.0.*
     , vector >=0.12 && <0.14
diff --git a/src/Data/Function/FastMemo.hs b/src/Data/Function/FastMemo.hs
--- a/src/Data/Function/FastMemo.hs
+++ b/src/Data/Function/FastMemo.hs
@@ -7,6 +7,7 @@
 import Data.Function.FastMemo.Char ()
 import Data.Function.FastMemo.Class (Memoizable (..))
 import Data.Function.FastMemo.Containers ()
+import Data.Function.FastMemo.DList ()
 import Data.Function.FastMemo.Instances ()
 import Data.Function.FastMemo.Int ()
 import Data.Function.FastMemo.Integer ()
diff --git a/src/Data/Function/FastMemo/DList.hs b/src/Data/Function/FastMemo/DList.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/Function/FastMemo/DList.hs
@@ -0,0 +1,11 @@
+{-# LANGUAGE DerivingVia #-}
+{-# LANGUAGE StandaloneDeriving #-}
+{-# OPTIONS_GHC -Wno-orphans #-}
+
+module Data.Function.FastMemo.DList where
+
+import Data.DList (DList)
+import Data.Function.FastMemo.Class (Memoizable)
+import Data.Function.FastMemo.List (AsList (..))
+
+deriving via AsList (DList a) instance Memoizable a => Memoizable (DList a)
diff --git a/src/Data/Function/FastMemo/Int.hs b/src/Data/Function/FastMemo/Int.hs
--- a/src/Data/Function/FastMemo/Int.hs
+++ b/src/Data/Function/FastMemo/Int.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DerivingVia #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -Wno-orphans #-}
@@ -10,20 +11,18 @@
 import Data.Int
 import Data.Word
 
-deriving via IntegralConversion Int Word instance Memoizable Int
+deriving via IntegralConversion Word Int instance Memoizable Int
 
-deriving via IntegralConversion Int8 Word8 instance Memoizable Int8
+deriving via IntegralConversion Word8 Int8 instance Memoizable Int8
 
-deriving via IntegralConversion Int16 Word16 instance Memoizable Int16
+deriving via IntegralConversion Word16 Int16 instance Memoizable Int16
 
-deriving via IntegralConversion Int32 Word32 instance Memoizable Int32
+deriving via IntegralConversion Word32 Int32 instance Memoizable Int32
 
-deriving via IntegralConversion Int64 Word64 instance Memoizable Int64
+deriving via IntegralConversion Word64 Int64 instance Memoizable Int64
 
-newtype IntegralConversion a b = IntegralConversion {getIntegralConversion :: a}
+newtype IntegralConversion b a = IntegralConversion a
+  deriving (Enum, Num, Eq, Ord, Real, Integral)
 
-instance (Integral a, Integral b, Memoizable b) => Memoizable (IntegralConversion a b) where
-  memoize f =
-    memoize (f . IntegralConversion . fromIntegral)
-      . (fromIntegral :: a -> b)
-      . getIntegralConversion
+instance (Integral a, Integral b, Memoizable b) => Memoizable (IntegralConversion b a) where
+  memoize f = memoize (f . fromIntegral) . (fromIntegral :: IntegralConversion b a -> b)
diff --git a/src/Data/Function/FastMemo/Integer.hs b/src/Data/Function/FastMemo/Integer.hs
--- a/src/Data/Function/FastMemo/Integer.hs
+++ b/src/Data/Function/FastMemo/Integer.hs
@@ -18,10 +18,10 @@
 
 integerToSignedNat :: Integer -> (Sign, Natural)
 integerToSignedNat i
-  | i < 0 = (NegativePlus1, fromInteger (- (i + 1)))
+  | i < 0 = (NegativePlus1, fromInteger (-(i + 1)))
   | otherwise = (NonNegative, fromInteger i)
 
 signedNatToInteger :: (Sign, Natural) -> Integer
 signedNatToInteger = \case
-  (NegativePlus1, n) -> - (toInteger n + 1)
+  (NegativePlus1, n) -> -(toInteger n + 1)
   (NonNegative, n) -> toInteger n
diff --git a/src/Data/Function/FastMemo/List.hs b/src/Data/Function/FastMemo/List.hs
--- a/src/Data/Function/FastMemo/List.hs
+++ b/src/Data/Function/FastMemo/List.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
 {-# OPTIONS_GHC -Wno-orphans #-}
 
@@ -14,6 +15,7 @@
 instance Memoizable a => Memoizable (NonEmpty a)
 
 newtype AsList t = AsList {unAsList :: t}
+  deriving (IsList)
 
 instance (IsList t, Memoizable (IsList.Item t)) => Memoizable (AsList t) where
-  memoize f = memoize (f . AsList . IsList.fromList) . IsList.toList . unAsList
+  memoize f = memoize (f . IsList.fromList) . IsList.toList
diff --git a/src/Data/Function/FastMemo/Util.hs b/src/Data/Function/FastMemo/Util.hs
--- a/src/Data/Function/FastMemo/Util.hs
+++ b/src/Data/Function/FastMemo/Util.hs
@@ -12,7 +12,7 @@
 memoizeFixedLen n f
   | n <= 0 = const (f [])
   | otherwise =
-    let f' = memoize $ \x -> memoizeFixedLen (n - 1) (f . (x :))
-     in \case
-          [] -> error "List too short"
-          x : xs -> f' x xs
+      let f' = memoize $ \x -> memoizeFixedLen (n - 1) (f . (x :))
+       in \case
+            [] -> error "List too short"
+            x : xs -> f' x xs
diff --git a/src/Data/Function/FastMemo/Word.hs b/src/Data/Function/FastMemo/Word.hs
--- a/src/Data/Function/FastMemo/Word.hs
+++ b/src/Data/Function/FastMemo/Word.hs
@@ -25,19 +25,18 @@
 
 deriving via MemoWord Word64 instance Memoizable Word64
 
-newtype MemoWord a = MemoWord {getMemoWord :: a}
+newtype MemoWord a = MemoWord a
 
 instance (FiniteBits a, Integral a) => Memoizable (MemoWord a) where
-  memoize f =
-    memoizeFixedLen (byteLen (0 :: a)) (f . MemoWord . fromBytes) . toBytes . getMemoWord
+  memoize f = memoizeFixedLen (byteLen (0 :: a)) (f . fromBytes) . toBytes
 
 byteLen :: FiniteBits a => a -> Int
 byteLen x = (finiteBitSize x + 7) `quot` 8
 
-toBytes :: (FiniteBits a, Integral a) => a -> [Word8]
-toBytes x = [fromIntegral (x `shiftR` i) | i <- [s0, s0 - 8 .. 0]]
+toBytes :: (FiniteBits a, Integral a) => MemoWord a -> [Word8]
+toBytes (MemoWord x) = [fromIntegral (x `shiftR` i) | i <- [s0, s0 - 8 .. 0]]
   where
     s0 = (byteLen x - 1) * 8
 
-fromBytes :: (Bits a, Num a) => [Word8] -> a
-fromBytes = foldl' (\acc x -> acc `shiftL` 8 .|. fromIntegral x) 0
+fromBytes :: (Bits a, Num a) => [Word8] -> MemoWord a
+fromBytes = MemoWord . foldl' (\acc x -> acc `shiftL` 8 .|. fromIntegral x) 0