diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,10 @@
 # Revision history for wide-word
 
+## 0.1.1.2 -- 2020-12-26
+
+* Derive Generic for Int128, Word128 and Word256.
+* Fix Bits.isSigned instance for Int128.
+
 ## 0.1.1.1 -- 2020-03-22
 
 * Make `sizeOf` and `alignment` methods of `Word256` `Prim` and `Storable`
diff --git a/src/Data/WideWord/Int128.hs b/src/Data/WideWord/Int128.hs
--- a/src/Data/WideWord/Int128.hs
+++ b/src/Data/WideWord/Int128.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE StrictData #-}
@@ -51,17 +52,22 @@
                 , subWordC#, timesWord#, timesWord2#, word2Int#, xor#)
 import GHC.Enum (predError, succError)
 import GHC.Exts ((+#), (*#), State#, Int#, Addr#, ByteArray#, MutableByteArray#)
+import GHC.Generics
 import GHC.Int (Int64 (..))
 import GHC.Real ((%))
 import GHC.Word (Word64 (..), Word32, byteSwap64)
 
+#if WORD_SIZE_IN_BITS < 64
+import GHC.IntWord64
+#endif
+
 import Data.Primitive.Types (Prim (..), defaultSetByteArray#, defaultSetOffAddr#)
 
 data Int128 = Int128
   { int128Hi64 :: !Word64
   , int128Lo64 :: !Word64
   }
-  deriving (Eq, Data, Ix, Typeable)
+  deriving (Eq, Data, Generic, Ix, Typeable)
 
 byteSwapInt128 :: Int128 -> Int128
 byteSwapInt128 (Int128 a1 a0) = Int128 (byteSwap64 a0) (byteSwap64 a1)
@@ -116,7 +122,7 @@
 
   bitSize _ = 128
   bitSizeMaybe _ = Just 128
-  isSigned _ = False
+  isSigned _ = True
 
   testBit = testBit128
   bit = bit128
diff --git a/src/Data/WideWord/Word128.hs b/src/Data/WideWord/Word128.hs
--- a/src/Data/WideWord/Word128.hs
+++ b/src/Data/WideWord/Word128.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE StrictData #-}
 {-# LANGUAGE UnboxedTuples #-}
@@ -46,9 +47,13 @@
                 , quotRemWord2#, subWordC#, timesWord#, timesWord2#, xor#)
 import GHC.Enum (predError, succError)
 import GHC.Exts ((*#), (+#), Int#, State#, ByteArray#, MutableByteArray#, Addr#)
+import GHC.Generics
 import GHC.Real ((%), divZeroError)
 import GHC.Word (Word64 (..), Word32, byteSwap64)
 
+#if WORD_SIZE_IN_BITS < 64
+import GHC.IntWord64
+#endif
 
 import Numeric (showHex)
 
@@ -58,7 +63,7 @@
   { word128Hi64 :: !Word64
   , word128Lo64 :: !Word64
   }
-  deriving (Eq, Data, Ix, Typeable)
+  deriving (Eq, Data, Generic, Ix, Typeable)
 
 byteSwapWord128 :: Word128 -> Word128
 byteSwapWord128 (Word128 a1 a0) = Word128 (byteSwap64 a0) (byteSwap64 a1)
diff --git a/src/Data/WideWord/Word256.hs b/src/Data/WideWord/Word256.hs
--- a/src/Data/WideWord/Word256.hs
+++ b/src/Data/WideWord/Word256.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE StrictData #-}
 {-# LANGUAGE UnboxedTuples #-}
@@ -45,9 +46,13 @@
                 , subWordC#, timesWord#, timesWord2#, xor#)
 import GHC.Enum (predError, succError)
 import GHC.Exts ((*#), (+#), Int#, State#, ByteArray#, MutableByteArray#, Addr#)
+import GHC.Generics
 import GHC.Real ((%))
 import GHC.Word (Word64 (..), Word32)
 
+#if WORD_SIZE_IN_BITS < 64
+import GHC.IntWord64
+#endif
 
 import Numeric (showHex)
 
@@ -59,7 +64,7 @@
   , word256m0 :: !Word64
   , word256lo :: !Word64
   }
-  deriving (Eq, Data, Ix, Typeable)
+  deriving (Eq, Data, Generic, Ix, Typeable)
 
 showHexWord256 :: Word256 -> String
 showHexWord256 (Word256 a3 a2 a1 a0)
diff --git a/wide-word.cabal b/wide-word.cabal
--- a/wide-word.cabal
+++ b/wide-word.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                wide-word
-version:             0.1.1.1
+version:             0.1.1.2
 synopsis:            Data types for large but fixed width signed and unsigned integers
 description:
   A library to provide data types for large (ie > 64 bits) but fixed width signed
@@ -25,7 +25,7 @@
 stability:           provisional
 cabal-version:       >= 1.10
 tested-with:         GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.4,
-                     GHC == 8.6.5, GHC == 8.8.3
+                     GHC == 8.6.5, GHC == 8.8.3, GHC == 8.10.1
 
 library
   default-language:   Haskell2010
@@ -38,7 +38,7 @@
                        Data.WideWord.Word256
                        Data.WideWord.Int128
 
-  build-depends:       base                          >= 4.9         && < 4.14
+  build-depends:       base                          >= 4.9         && < 4.15
                      , deepseq                       >= 1.3         && < 1.5
                      , primitive                     >= 0.6.4.0     && < 0.8