1 files changed, 4 insertions, 3 deletions

diff --git a/dht/src/Codec/AsciiKey256.hs b/dht/src/Codec/AsciiKey256.hs
index ee17b7c1..1738a368 100644
--- a/dht/src/Codec/AsciiKey256.hs
+++ b/dht/src/Codec/AsciiKey256.hs
@@ -3,6 +3,7 @@ module Codec.AsciiKey256 where
 
 import Control.Applicative
 import Control.Monad
+import Control.Monad.Fail                     as MF
 import Data.Bits
 import qualified Data.ByteArray               as BA
          ;import Data.ByteArray               as BA (ByteArrayAccess)
@@ -112,7 +113,7 @@ readsPrecKey256 publicKey str
         | otherwise = []
 
 
-parseKey256 :: (Monad m, Alternative m) => String -> m ByteString
+parseKey256 :: (MonadFail m, Alternative m) => String -> m ByteString
 parseKey256 nidstr = do
         let nidbs  = C8.pack nidstr
             (bs,_) = Base16.decode nidbs
@@ -121,7 +122,7 @@ parseKey256 nidstr = do
                         43 -> parseToken32 nidstr
                         _  -> Left "Wrong size of key."
         idbs <- (guard (B.length bs == 32) >> return bs)
-                <|> either fail return enid
+                <|> either MF.fail return enid
         return idbs
 
 readP_key256 :: RP.ReadP ByteString
@@ -131,7 +132,7 @@ readP_key256 = do
         , fmap (32,) (sequence $ replicate 52 (RP.satisfy zb32digit))
         , fmap (64,) (sequence $ replicate 43 (RP.satisfy b64digit))
         ]
-      let failure = fail "Bad key."
+      let failure = MF.fail "Bad key."
       case is64 of
         32 -> case parse32Token32 hexhash of
                   Right bs -> return bs