diff --git a/checkers.cabal b/checkers.cabal
--- a/checkers.cabal
+++ b/checkers.cabal
@@ -1,5 +1,5 @@
 Name:                checkers
-Version:             0.4.9
+Version:             0.4.9.2
 Cabal-Version:       >= 1.6
 Synopsis:            Check properties on standard classes and data structures.
 Category:            Testing
@@ -28,7 +28,7 @@
 Library
   hs-Source-Dirs:      src
   Extensions:
-  Build-Depends:       base < 5, random, QuickCheck>=2.3, array >= 0.1, semigroupoids >= 5 && < 6
+  Build-Depends:       base >= 4.8 && < 5, random, QuickCheck>=2.3, array >= 0.1, semigroupoids >= 5 && < 6
   Exposed-Modules:
                        Test.QuickCheck.Utils
                        Test.QuickCheck.Checkers
diff --git a/src/Test/QuickCheck/Checkers.hs b/src/Test/QuickCheck/Checkers.hs
--- a/src/Test/QuickCheck/Checkers.hs
+++ b/src/Test/QuickCheck/Checkers.hs
@@ -43,8 +43,8 @@
   , arbitrarySatisfying
   ) where
 
--- import Data.Function (on)
 import Data.Function (on)
+import Data.Monoid (Monoid (mempty, mappend))
 import Control.Applicative
 import Control.Arrow ((***),first)
 import qualified Control.Exception as Ex
diff --git a/src/Test/QuickCheck/Classes.hs b/src/Test/QuickCheck/Classes.hs
--- a/src/Test/QuickCheck/Classes.hs
+++ b/src/Test/QuickCheck/Classes.hs
@@ -28,6 +28,7 @@
   )
   where
 
+import Control.Applicative ((<$>))
 import Data.Foldable (foldMap)
 import Data.Functor.Apply (Apply ((<.>)))
 import Data.Functor.Alt (Alt ((<!>)))
diff --git a/src/Test/QuickCheck/Instances/Array.hs b/src/Test/QuickCheck/Instances/Array.hs
--- a/src/Test/QuickCheck/Instances/Array.hs
+++ b/src/Test/QuickCheck/Instances/Array.hs
@@ -1,6 +1,7 @@
 {-# OPTIONS_GHC -Wall -fno-warn-orphans #-}
 module Test.QuickCheck.Instances.Array where
 
+import Control.Applicative ((<$>))
 import Test.QuickCheck
 import Data.Array
 
diff --git a/src/Test/QuickCheck/Instances/Maybe.hs b/src/Test/QuickCheck/Instances/Maybe.hs
--- a/src/Test/QuickCheck/Instances/Maybe.hs
+++ b/src/Test/QuickCheck/Instances/Maybe.hs
@@ -1,5 +1,6 @@
 module Test.QuickCheck.Instances.Maybe (maybeGen) where
 
+import Control.Applicative (pure, (<$>))
 import Test.QuickCheck
 
 maybeGen :: Gen a -> Gen (Maybe a)
diff --git a/src/Test/QuickCheck/Instances/Num.hs b/src/Test/QuickCheck/Instances/Num.hs
--- a/src/Test/QuickCheck/Instances/Num.hs
+++ b/src/Test/QuickCheck/Instances/Num.hs
@@ -4,6 +4,7 @@
        ,nonZero,nonZero_
        ) where
 
+import Control.Applicative ((<$>))
 import Test.QuickCheck
 import Control.Monad.Extensions