diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -27,3 +27,8 @@
 # Credit
 All credit goes to the original pHash authors. For more information about pHash
 visit http://phash.org
+
+# Contributors
+
+* [Michael Xavier](http://github.com/MichaelXavier)
+* [Hans Raaf](https://github.com/oderwat)
diff --git a/phash.cabal b/phash.cabal
--- a/phash.cabal
+++ b/phash.cabal
@@ -1,5 +1,5 @@
 name:               phash
-version:            0.0.3
+version:            0.0.4
 synopsis:           Haskell bindings to pHash, the open source perceptual hash library
 description:        See http://www.phash.org/ for more info. Note that you
                     must have libphash installed on your system to use this
@@ -16,28 +16,40 @@
 homepage:           http://github.com/michaelxavier/phash
 bug-reports:        http://github.com/michaelxavier/phash/issues
 
+flag lib-Werror
+  default: False
+  manual: True
+
 library
   exposed-modules:  Data.PHash
   exposed-modules:  Data.PHash.Image
   exposed-modules:  Data.PHash.Types
-  build-depends:    base >= 4.6 && < 4.8
+  build-depends:    base >= 4.6 && < 4.9
   hs-source-dirs:   src
   default-language: Haskell2010
   extra-libraries:  pHash
+  if flag(lib-Werror)
+    ghc-options: -Werror
 
+  ghc-options: -Wall
+
 test-suite spec
   type:             exitcode-stdio-1.0
   main-is:          Test.hs
   default-language: Haskell2010
   hs-source-dirs:   src, test
   extra-libraries:  pHash
-  build-depends:    base >= 4.6 && < 4.8
+  build-depends:    base
   build-depends:    tasty >= 0.7 && < 1.0
   build-depends:    tasty-smallcheck >= 0.2 && < 1.0
   build-depends:    tasty-hunit >= 0.4.1 && < 1.0
   build-depends:    HUnit >= 1.2.5.2 && < 2.0
   build-depends:    smallcheck
+  if flag(lib-Werror)
+    ghc-options: -Werror
 
+  ghc-options: -Wall
+
 test-suite docs
   type:             exitcode-stdio-1.0
   main-is:          DocTest.hs
@@ -45,7 +57,7 @@
   hs-source-dirs:   src, test
   extra-libraries:  pHash
   ghc-options:      -threaded
-  build-depends:    base >= 4.6 && < 4.8
+  build-depends:    base
   build-depends:    doctest >= 0.9.10 && < 1.0
   build-depends:    phash
 
diff --git a/src/Data/PHash.hs b/src/Data/PHash.hs
--- a/src/Data/PHash.hs
+++ b/src/Data/PHash.hs
@@ -4,12 +4,13 @@
                   , module Data.PHash.Image
                   , module Data.PHash.Types ) where
 
-import Control.Applicative ( (<$>)
-                           , (<*>) )
-import Foreign.C.Types
+import           Control.Applicative
+import           Foreign.C.Types
 
-import Data.PHash.Image
-import Data.PHash.Types
+import           Prelude
+
+import           Data.PHash.Image
+import           Data.PHash.Types
 
 {-|
 Calculate the distance between two hashes. This can be used to detect how
diff --git a/src/Data/PHash/Image.hs b/src/Data/PHash/Image.hs
--- a/src/Data/PHash/Image.hs
+++ b/src/Data/PHash/Image.hs
@@ -1,12 +1,14 @@
 {-# LANGUAGE ForeignFunctionInterface #-}
 module Data.PHash.Image ( imageHash ) where
 
-import Control.Applicative ((<$>))
-import Foreign
-import Foreign.C.String
-import Foreign.C.Types
+import           Control.Applicative
+import           Foreign
+import           Foreign.C.String
+import           Foreign.C.Types
 
-import Data.PHash.Types
+import           Prelude
+
+import           Data.PHash.Types
 
 -- $setup
 -- >>> let imgPath = "test/fixtures/grump.jpg"
diff --git a/test/Test.hs b/test/Test.hs
--- a/test/Test.hs
+++ b/test/Test.hs
@@ -1,13 +1,17 @@
-{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
-import Control.Applicative
-import Test.Tasty
-import Test.Tasty.SmallCheck
-import Test.Tasty.HUnit
-import Test.SmallCheck.Series
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+import           Control.Applicative
+import           Test.SmallCheck.Series
+import           Test.Tasty
+import           Test.Tasty.HUnit
+import           Test.Tasty.SmallCheck
 
-import Data.PHash
+import           Prelude
 
+import           Data.PHash
+
+main :: IO ()
 main = defaultMain tests
 
 tests :: TestTree