diff --git a/ip.cabal b/ip.cabal
--- a/ip.cabal
+++ b/ip.cabal
@@ -1,5 +1,5 @@
 name: ip
-version: 1.1.0
+version: 1.1.1
 synopsis: Library for IP and MAC addresses
 homepage: https://github.com/andrewthad/haskell-ip#readme
 license: BSD3
@@ -70,7 +70,7 @@
     , test-framework
     , test-framework-quickcheck2
     , QuickCheck
-    , quickcheck-classes
+    , quickcheck-classes >= 0.3 && < 0.4
     , text
     , bytestring
     , HUnit
diff --git a/src/Net/IPv4.hs b/src/Net/IPv4.hs
--- a/src/Net/IPv4.hs
+++ b/src/Net/IPv4.hs
@@ -399,12 +399,12 @@
 instance FromJSON IPv4 where
   parseJSON = Aeson.withText "IPv4" aesonParser
 
+#if MIN_VERSION_aeson(1,0,0) 
 instance ToJSONKey IPv4 where
   toJSONKey = ToJSONKeyText
     encode
     (\addr -> Aeson.unsafeToEncoding $ BB.char7 '"' <> builderUtf8 addr <> BB.char7 '"')
 
-#if MIN_VERSION_aeson(1,0,0) 
 instance FromJSONKey IPv4 where
   fromJSONKey = FromJSONKeyTextParser aesonParser
 #endif
diff --git a/src/Net/IPv4/Range.hs b/src/Net/IPv4/Range.hs
--- a/src/Net/IPv4/Range.hs
+++ b/src/Net/IPv4/Range.hs
@@ -8,7 +8,8 @@
 {-# OPTIONS_GHC -Wall #-}
 module Net.IPv4.Range
   ( -- * Range functions
-    normalize
+    range
+  , normalize
   , contains
   , member
   , lowerInclusive
@@ -65,6 +66,11 @@
 -- >>> instance Arbitrary IPv4 where { arbitrary = fmap IPv4 arbitrary }
 -- >>> instance Arbitrary IPv4Range where { arbitrary = IPv4Range <$> arbitrary <*> arbitrary }
 --
+
+-- | Smart constructor for 'IPv4Range'. Ensures the mask is appropriately
+--   sized and sets masked bits in the 'IPv4' to zero.
+range :: IPv4 -> Word8 -> IPv4Range
+range addr len = normalize (IPv4Range addr len)
 
 -- | Checks to see if an 'IPv4' address belongs in the 'IPv4Range'.
 --
diff --git a/test/Test.hs b/test/Test.hs
--- a/test/Test.hs
+++ b/test/Test.hs
@@ -9,12 +9,12 @@
 import Data.Proxy (Proxy(..))
 import Test.Framework (defaultMain, testGroup, Test)
 import Test.Framework.Providers.QuickCheck2 (testProperty)
-import Test.QuickCheck (Arbitrary(..),Property,oneof,Gen,elements)
+import Test.QuickCheck (Arbitrary(..),Property,oneof,Gen,elements,choose)
 import Test.HUnit (Assertion,(@?=))
 import Numeric (showHex)
 import Test.QuickCheck.Property (failed,succeeded,Result(..))
 import Data.Bifunctor
-import Test.QuickCheck.Classes (jsonProps,showReadProps)
+import Test.QuickCheck.Classes (Laws(..),jsonLaws,showReadLaws)
 import qualified Test.Framework.Providers.HUnit as PH
 
 import Net.Types (IP,IPv4(..),IPv4Range(..),Mac(..),IPv6(..),MacGrouping(..),MacCodec(..))
@@ -97,26 +97,30 @@
     ]
   , testGroup "Instances"
     [ testGroup "IPv4"
-      [ namedPropertiesToTest "JSON" (jsonProps (Proxy :: Proxy IPv4))
-      , namedPropertiesToTest "Show Read" (showReadProps (Proxy :: Proxy IPv4))
+      [ lawsToTest (jsonLaws (Proxy :: Proxy IPv4))
+      , lawsToTest (showReadLaws (Proxy :: Proxy IPv4))
       ]
+    , testGroup "IPv4Range"
+      [ lawsToTest (jsonLaws (Proxy :: Proxy IPv4Range))
+      , lawsToTest (showReadLaws (Proxy :: Proxy IPv4Range))
+      ]
     , testGroup "IPv6"
-      [ namedPropertiesToTest "JSON" (jsonProps (Proxy :: Proxy IPv6))
-      , namedPropertiesToTest "Show Read" (showReadProps (Proxy :: Proxy IPv6))
+      [ lawsToTest (jsonLaws (Proxy :: Proxy IPv6))
+      , lawsToTest (showReadLaws (Proxy :: Proxy IPv6))
       ]
     , testGroup "IP"
-      [ namedPropertiesToTest "JSON" (jsonProps (Proxy :: Proxy IP))
-      , namedPropertiesToTest "Show Read" (showReadProps (Proxy :: Proxy IP))
+      [ lawsToTest (jsonLaws (Proxy :: Proxy IP))
+      , lawsToTest (showReadLaws (Proxy :: Proxy IP))
       ]
     , testGroup "Mac"
-      [ namedPropertiesToTest "JSON" (jsonProps (Proxy :: Proxy Mac))
-      , namedPropertiesToTest "Show Read" (showReadProps (Proxy :: Proxy Mac))
+      [ lawsToTest (jsonLaws (Proxy :: Proxy Mac))
+      , lawsToTest (showReadLaws (Proxy :: Proxy Mac))
       ]
     ]
   ]
 
-namedPropertiesToTest :: String -> [(String,Property)] -> Test
-namedPropertiesToTest name pairs = testGroup name (map (uncurry testProperty) pairs)
+lawsToTest :: Laws -> Test
+lawsToTest (Laws name pairs) = testGroup name (map (uncurry testProperty) pairs)
 
 propEncodeDecodeIso :: Eq a => (a -> b) -> (b -> Maybe a) -> a -> Bool
 propEncodeDecodeIso f g a = g (f a) == Just a
@@ -339,8 +343,7 @@
 -- This instance can generate masks that exceed the recommended
 -- length of 32.
 instance Arbitrary IPv4Range where
-  arbitrary = fmap fromTuple arbitrary
-    where fromTuple (a,b) = IPv4Range a b
+  arbitrary = IPv4Range.range <$> arbitrary <*> choose (0,32)
 
 instance Arbitrary MacCodec where
   arbitrary = MacCodec <$> arbitrary <*> arbitrary