diff --git a/Data/ByteString/Base64.hs b/Data/ByteString/Base64.hs
--- a/Data/ByteString/Base64.hs
+++ b/Data/ByteString/Base64.hs
@@ -1,4 +1,7 @@
-{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE CPP #-}
+#if __GLASGOW_HASKELL__ >= 702
+{-# LANGUAGE Trustworthy #-}
+#endif
 
 -- |
 -- Module      : Data.ByteString.Base64
diff --git a/Data/ByteString/Base64/URL.hs b/Data/ByteString/Base64/URL.hs
--- a/Data/ByteString/Base64/URL.hs
+++ b/Data/ByteString/Base64/URL.hs
@@ -1,4 +1,7 @@
-{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE CPP #-}
+#if __GLASGOW_HASKELL__ >= 702
+{-# LANGUAGE Trustworthy #-}
+#endif
 
 -- |
 -- Module      : Data.ByteString.Base64.URL
diff --git a/base64-bytestring.cabal b/base64-bytestring.cabal
--- a/base64-bytestring.cabal
+++ b/base64-bytestring.cabal
@@ -1,5 +1,5 @@
 name:                base64-bytestring
-version:             0.1.1.1
+version:             0.1.1.3
 synopsis:            Fast base64 encoding and deconding for ByteStrings
 description:         Fast base64 encoding and deconding for ByteStrings
 homepage:            https://github.com/bos/base64-bytestring
@@ -29,7 +29,7 @@
 
   build-depends:
     base == 4.*,
-    bytestring == 0.9.*
+    bytestring >= 0.9.0
 
   ghc-options: -Wall -funbox-strict-fields
   ghc-prof-options: -auto-all
diff --git a/benchmarks/BM.hs b/benchmarks/BM.hs
--- a/benchmarks/BM.hs
+++ b/benchmarks/BM.hs
@@ -3,7 +3,7 @@
 import Criterion.Main
 import qualified Data.ByteString.Char8 as B
 import qualified Data.ByteString.Base64 as B
-import qualified Data.ByteString.Base64 as U
+import qualified Data.ByteString.Base64.URL as U
 
 sized name orig =
     bgroup name [
diff --git a/tests/Tests.hs b/tests/Tests.hs
new file mode 100644
--- /dev/null
+++ b/tests/Tests.hs
@@ -0,0 +1,116 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+module Main (main) where
+
+import Test.Framework (Test, defaultMain, testGroup)
+import Test.Framework.Providers.QuickCheck2 (testProperty)
+import Test.Framework.Providers.HUnit (testCase)
+
+import Test.QuickCheck (Arbitrary(..))
+
+import Control.Monad (liftM)
+import qualified Data.ByteString.Base64 as Base64
+import qualified Data.ByteString.Base64.URL as Base64URL
+import Data.ByteString (ByteString)
+import Data.ByteString.Char8 ()
+import qualified Data.ByteString as B
+import Test.HUnit hiding (Test)
+
+
+main :: IO ()
+main = defaultMain tests
+
+tests :: [Test]
+tests = [ 
+    testGroup "Base64" [
+        testProperty "decodeEncode" $
+          genericDecodeEncode Base64.encode Base64.decode
+      , testProperty "decodeEncode Lenient" $
+          genericDecodeEncode Base64.encode
+                              (liftM Right Base64.decodeLenient)
+      , testGroup "base64-string tests" base64_string_tests 
+    ]
+  , testGroup "Base64URL" [
+        testProperty "decodeEncode" $
+          genericDecodeEncode Base64URL.encode Base64URL.decode
+      , testProperty "decodeEncode Lenient" $
+          genericDecodeEncode Base64URL.encode
+                              (liftM Right Base64URL.decodeLenient)
+      , testGroup "base64-string tests" base64url_string_tests 
+    ]
+  ]
+
+instance Arbitrary ByteString where
+  arbitrary = liftM B.pack arbitrary
+
+-- | Decoding an encoded sintrg should produce the original string.
+genericDecodeEncode :: (ByteString -> ByteString)
+                    -> (ByteString -> Either String ByteString)
+                    -> ByteString -> Bool
+genericDecodeEncode enc dec x = case dec (enc x) of
+                                  Left  _  -> False
+                                  Right x' -> x == x'
+  
+--
+-- Unit tests from base64-string
+-- Copyright (c) Ian Lynagh, 2005, 2007.
+--
+
+base64_string_tests :: [Test]
+base64_string_tests = 
+  base64_string_test Base64.encode Base64.decode testData ++
+  base64_string_test Base64.encode decodeURL testData
+  where decodeURL :: ByteString -> Either String ByteString
+        decodeURL = liftM Right Base64.decodeLenient
+        testData :: [(ByteString, ByteString)]
+        testData = [("",                "")
+                   ,("\0",              "AA==")
+                   ,("\255",            "/w==")
+                   ,("E",               "RQ==")
+                   ,("Ex",              "RXg=")
+                   ,("Exa",             "RXhh")
+                   ,("Exam",            "RXhhbQ==")
+                   ,("Examp",           "RXhhbXA=")
+                   ,("Exampl",          "RXhhbXBs")
+                   ,("Example",         "RXhhbXBsZQ==")
+                   ,("Ex\0am\254ple",   "RXgAYW3+cGxl")
+                   ,("Ex\0am\255ple",   "RXgAYW3/cGxl")
+                   ]
+
+-- | Same as the base64_string_tests but using the alternative alphabet
+base64url_string_tests :: [Test]
+base64url_string_tests =
+  base64_string_test Base64URL.encode Base64URL.decode testData ++
+  base64_string_test Base64URL.encode decodeURL testData
+  where decodeURL :: ByteString -> Either String ByteString
+        decodeURL = liftM Right Base64URL.decodeLenient
+        testData :: [(ByteString, ByteString)]
+        testData = [("",                "")
+                   ,("\0",              "AA==")
+                   ,("\255",            "_w==")
+                   ,("E",               "RQ==")
+                   ,("Ex",              "RXg=")
+                   ,("Exa",             "RXhh")
+                   ,("Exam",            "RXhhbQ==")
+                   ,("Examp",           "RXhhbXA=")
+                   ,("Exampl",          "RXhhbXBs")
+                   ,("Example",         "RXhhbXBsZQ==")
+                   ,("Ex\0am\254ple",   "RXgAYW3-cGxl")
+                   ,("Ex\0am\255ple",   "RXgAYW3_cGxl")
+                   ]
+
+-- | Generic test given encod enad decode funstions and a
+-- list of (plain, encoded) pairs
+base64_string_test :: (ByteString -> ByteString)
+                   -> (ByteString -> Either String ByteString)
+                   -> [(ByteString, ByteString)] -> [Test]
+base64_string_test enc dec testData = concat
+      [ [ testCase ("base64-string: Encode " ++ show plain)
+                   (encoded_plain @?= encoded),
+          testCase ("base64-string: Decode " ++ show plain)
+                   (decoded_encoded @?= Right plain) ]
+      | (plain, encoded) <- testData,
+        let encoded_plain = enc plain
+            decoded_encoded = dec encoded
+      ]