diff --git a/src/Data/UniformPair.hs b/src/Data/UniformPair.hs
--- a/src/Data/UniformPair.hs
+++ b/src/Data/UniformPair.hs
@@ -1,6 +1,16 @@
-{-# LANGUAGE DeriveFunctor, DeriveFoldable, DeriveTraversable #-}
+{-# LANGUAGE CPP, DeriveFunctor, DeriveFoldable, DeriveTraversable #-}
 {-# OPTIONS_GHC -Wall #-}
-
+#if MIN_VERSION_base(4,9,0)
+#define LIFTED_FUNCTOR_CLASSES 1
+#else
+#if MIN_VERSION_transformers(0,5,0)
+#define LIFTED_FUNCTOR_CLASSES 1
+#else
+#if MIN_VERSION_transformers_compat(0,5,0) && !MIN_VERSION_transformers(0,4,0)
+#define LIFTED_FUNCTOR_CLASSES 1
+#endif
+#endif
+#endif
 ----------------------------------------------------------------------
 -- |
 -- Module      :  Data.UniformPair
@@ -24,14 +34,16 @@
   ( Pair(..), fstP,sndP, firstP, secondP, getP, onElemP, swapP, compareSwap
   ) where
 
-import Data.Monoid (Monoid(..),(<>))
+import Data.Monoid (Monoid(..))
+import Data.Semigroup (Semigroup (..))
 import Data.Functor ((<$>))
 import Data.Foldable (Foldable(..))
 import Data.Traversable (Traversable(..))
+import Data.Functor.Classes (Eq1(..), Ord1(..), Show1(..))
 import Control.Applicative (Applicative(..)) -- ,liftA2
 import Control.DeepSeq (NFData(..))
 
-import Prelude.Extras (Show1(..))
+import qualified Prelude.Extras as PE (Eq1, Ord1, Show1)
 
 infix 1 :#
 
@@ -43,8 +55,29 @@
 instance NFData a => NFData (Pair a) where
     rnf (a :# b) = rnf a `seq` rnf b
 
-instance Show1 Pair
+instance PE.Eq1 Pair
+instance PE.Ord1 Pair
+instance PE.Show1 Pair
 
+#if LIFTED_FUNCTOR_CLASSES
+instance Eq1 Pair where
+  liftEq eq (a :# b) (c :# d) = eq a c && eq b d
+
+instance Ord1 Pair where
+  liftCompare cmp (a :# b) (c :# d) = cmp a c `mappend` cmp b d
+
+instance Show1 Pair where
+  liftShowsPrec sp _sl d (a :# b) = showParen (d > 1) $
+    sp 2 a . showString " :# " . sp 2 b
+#else
+instance Eq1 Pair where
+  eq1 = (==)
+instance Ord1 Pair where
+  compare1 = compare
+instance Show1 Pair where
+  showsPrec1 = showsPrec
+#endif
+
 fstP :: Pair a -> a
 fstP (a :# _) = a
 
@@ -59,9 +92,12 @@
 -- unzipP ps = (fstP <$> ps) :# (sndP <$> ps)
 -- unzipP = liftA2 (:#) (fmap fstP) (fmap sndP)
 
+instance Semigroup a => Semigroup (Pair a) where
+  (a :# b) <> (c :# d) = (a <> c) :# (b <> d)
+
 instance Monoid a => Monoid (Pair a) where
   mempty = mempty :# mempty
-  (a :# b) `mappend` (c :# d) = (a <> c) :# (b <> d)  -- exchange
+  (a :# b) `mappend` (c :# d) = (a `mappend` c) :# (b `mappend` d)  -- exchange
 
 instance Applicative Pair where
   pure a = a :# a
diff --git a/uniform-pair.cabal b/uniform-pair.cabal
--- a/uniform-pair.cabal
+++ b/uniform-pair.cabal
@@ -1,10 +1,14 @@
 Name:                uniform-pair
-Version:             0.1.12
+Version:             0.1.13
 Cabal-Version:       >= 1.6
 Synopsis:            Uniform pairs with class instances
 Category:            Data
 Description:
   Uniform pairs with class instances
+  .
+  @
+  data Pair a = a :# a
+  @
 Author:              Conal Elliott
 Maintainer:          conal@conal.net
 Copyright:           (c) 2013 by Conal Elliott
@@ -14,6 +18,14 @@
 Stability:           experimental
 build-type:          Simple
 data-files:          changelog
+tested-with:
+  GHC==8.0.2,
+  GHC==7.10.3,
+  GHC==7.8.4,
+  GHC==7.6.3,
+  GHC==7.4.2,
+  GHC==7.2.2,
+  GHC==7.0.4
 
 source-repository head
   type:     git
@@ -23,6 +35,8 @@
   hs-Source-Dirs:      src
   Extensions:
   Build-Depends:       base<5, prelude-extras < 0.5, deepseq
-  Exposed-Modules:     
+  Exposed-Modules:
                        Data.UniformPair
   ghc-options:         -Wall
+  if !impl(ghc >= 8.0)
+    Build-Depends:     semigroups >= 0.18.2, transformers >= 0.2, transformers-compat >= 0.4