diff --git a/Data/LargeWord.hs b/Data/LargeWord.hs
--- a/Data/LargeWord.hs
+++ b/Data/LargeWord.hs
@@ -127,7 +127,7 @@
 -- Define larger keys from smaller ones.
 
 data LargeKey a b = LargeKey a b
-   deriving (Eq, Ord)
+   deriving (Eq)
 
 {-# INLINE loHalf #-}
 loHalf :: LargeKey a b -> a
@@ -289,6 +289,9 @@
 instance (Binary a, Binary b) => Binary (LargeKey a b) where
    put (LargeKey lo hi) = put hi >> put lo
    get = flip LargeKey <$> get <*> get
+
+instance (Ord a, Ord b) => Ord (LargeKey a b) where
+    compare a b = compare (hiHalf a, loHalf a) (hiHalf b, loHalf b)
 
 type Word96  = LargeKey Word32 Word64
 type Word128 = LargeKey Word64 Word64
diff --git a/Tests/Properties.hs b/Tests/Properties.hs
--- a/Tests/Properties.hs
+++ b/Tests/Properties.hs
@@ -86,6 +86,9 @@
 u6 :: Assertion
 u6 = rotate ((2^95) :: Word96) (1) @?= 1
 
+u7 :: Assertion
+u7 = (2^64 :: Word128) < (2 :: Word128) @?= False
+
 tests :: [Test]
 tests =
     [ testProperty "largeword shift left then right" pShiftRightShiftLeft
@@ -107,6 +110,7 @@
     , testProperty "Word192 encode/decode loop" (encodeDecode::Word192 -> Bool)
     , testProperty "Word224 encode/decode loop" (encodeDecode::Word224 -> Bool)
     , testProperty "Word256 encode/decode loop" (encodeDecode::Word256 -> Bool)
+    , testCase "largeword Ord test" u7
       ]
 
 main :: IO ()
diff --git a/largeword.cabal b/largeword.cabal
--- a/largeword.cabal
+++ b/largeword.cabal
@@ -1,5 +1,5 @@
 name:           largeword
-version:        1.2.3
+version:        1.2.4
 license:        BSD3
 copyright:      Dominic Steinitz <dominic@steinitz.org>
 author:         Dominic Steinitz <dominic@steinitz.org>
@@ -10,8 +10,8 @@
 category:       Data
 stability:      stable
 build-type:     Simple
-cabal-version:  >= 1.9.2
-tested-with:    GHC == 7.6.2, GHC == 7.8.2
+cabal-version:  >= 1.8
+tested-with:    GHC >= 6.12.3 && < 7.9
 -- Tests/Properties.hs shouldn't have to go here, but the source files
 -- for the test-suite stanzas don't get picked up by `cabal sdist`.
 Extra-source-files: Tests/Properties.hs
@@ -38,8 +38,3 @@
                  QuickCheck >= 2.4.0.1,
                  HUnit >= 1.2.2.3,
                  largeword == 1.2.3
-
-
-
-
-