diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -16,3 +16,4 @@
 * [Michael Hatfield](https://github.com/mikehat)
 * [reactormonk](https://github.com/reactormonk)
 * [Oleg Grenrus](https://github.com/phadej)
+* [Edward Betts](https://github.com/EdwardBetts)
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,7 @@
+0.3.0.0
+* Add MonadFail instance.
+* Correct haddock spelling mistake.
+
 0.2.3.3
 * Make buildable on GHC 8.2.1.
 
diff --git a/src/URI/ByteString/Internal.hs b/src/URI/ByteString/Internal.hs
--- a/src/URI/ByteString/Internal.hs
+++ b/src/URI/ByteString/Internal.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP                        #-}
 {-# LANGUAGE GADTs                      #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE OverloadedStrings          #-}
@@ -11,9 +12,10 @@
 import qualified Blaze.ByteString.Builder.Char.Utf8 as BB
 import           Control.Applicative
 import           Control.Monad
+import qualified Control.Monad.Fail                 as F
 import           Data.Attoparsec.ByteString
 import qualified Data.Attoparsec.ByteString         as A
-import qualified Data.Attoparsec.ByteString.Char8   as A ( decimal )
+import qualified Data.Attoparsec.ByteString.Char8   as A (decimal)
 import           Data.Bits
 import           Data.ByteString                    (ByteString)
 import qualified Data.ByteString                    as BS
@@ -794,6 +796,14 @@
                              , Monoid)
 
 
+instance F.MonadFail (Parser' e) where
+#if MIN_VERSION_attoparsec(0,13,1)
+  fail e = Parser' (F.fail e)
+#else
+  fail e = Parser' (fail e)
+#endif
+
+
 -------------------------------------------------------------------------------
 -- | Use with caution. Catch a parser failing and return Nothing.
 mParse :: Parser' e a -> Parser' e (Maybe a)
@@ -804,7 +814,7 @@
 -- | If the first parser succeeds, discard the result and use the
 -- second parser (which may fail). If the first parser fails, return
 -- Nothing. This is used to check a benign precondition that indicates
--- the presence of a parsible token, i.e. ? preceeding a query.
+-- the presence of a parsible token, i.e. ? preceding a query.
 thenJust :: Parser' e a -> Parser' e b -> Parser' e (Maybe b)
 thenJust p1 p2 = p1 *> (Just <$> p2) <|> pure Nothing
 
diff --git a/test/URI/ByteString/Arbitrary.hs b/test/URI/ByteString/Arbitrary.hs
--- a/test/URI/ByteString/Arbitrary.hs
+++ b/test/URI/ByteString/Arbitrary.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE ConstraintKinds       #-}
+{-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
@@ -9,6 +11,7 @@
 import           Control.Applicative
 import           Data.Proxy                (Proxy (..))
 import qualified Generics.SOP              as SOP
+import qualified Generics.SOP.Constraint   as SOP
 import qualified Generics.SOP.GGP          as SOP
 import           GHC.Generics              (Generic)
 import           Test.QuickCheck
@@ -22,11 +25,20 @@
 
 -- this workaround can go away when
 -- <https://github.com/nick8325/quickcheck/pull/40> is merged.
-sopArbitrary :: (Generic a, SOP.GTo a, SOP.All SOP.SListI (SOP.GCode a), SOP.All2 Arbitrary (SOP.GCode a)) => Gen a
+sopArbitrary
+  :: ( SOP.SListI (SOP.GCode b)
+     , Generic b
+     , SOP.GTo b
+     , SOP.AllF SOP.SListI (SOP.GCode b)
+     , SOP.AllF (SOP.All Arbitrary) (SOP.GCode b)
+     )
+  => Gen b
 sopArbitrary = fmap SOP.gto sopArbitrary'
 
 
-sopArbitrary' :: (SOP.All SOP.SListI xss, SOP.All2 Arbitrary xss) => Gen (SOP.SOP SOP.I xss)
+sopArbitrary'
+  :: (SOP.SListI xs, SOP.AllF (SOP.All Arbitrary) xs, SOP.AllF SOP.SListI xs)
+  => Gen (SOP.SOP SOP.I xs)
 sopArbitrary' = oneof (map SOP.hsequence $ SOP.apInjs_POP $ SOP.hcpure p arbitrary)
   where
     p :: Proxy Arbitrary
diff --git a/uri-bytestring.cabal b/uri-bytestring.cabal
--- a/uri-bytestring.cabal
+++ b/uri-bytestring.cabal
@@ -1,5 +1,5 @@
 name:                uri-bytestring
-version:             0.2.3.3
+version:             0.3.0.0
 synopsis:            Haskell URI parsing as ByteStrings
 description: uri-bytestring aims to be an RFC3986 compliant URI parser that uses efficient ByteStrings for parsing and representing the URI data.
 license:             BSD3
@@ -41,6 +41,7 @@
 
       attoparsec       >= 0.12    && < 0.14
     , base             >= 4.6     && < 5
+    , fail             >= 4.9     && < 5
     , bytestring       >= 0.9.1   && < 0.11
     , blaze-builder    >= 0.3.0.0 && < 0.5
     , template-haskell >= 2.9     && < 2.13