diff --git a/OpenId2/Discovery.hs b/OpenId2/Discovery.hs
--- a/OpenId2/Discovery.hs
+++ b/OpenId2/Discovery.hs
@@ -26,7 +26,7 @@
 -- Libraries
 import Data.Char
 import Data.Maybe
-import Network.HTTP.Enumerator
+import Network.HTTP.Conduit
 import qualified Data.ByteString.Char8 as S8
 import Control.Arrow (first)
 import Control.Monad.IO.Class (MonadIO (liftIO))
@@ -46,12 +46,7 @@
     deriving Show
 
 -- | Attempt to resolve an OpenID endpoint, and user identifier.
-discover :: ( MonadIO m
-            , Failure AuthenticateException m
-            , Failure HttpException m
-            )
-         => Identifier
-         -> m Discovery
+discover :: Identifier -> IO Discovery
 discover ident@(Identifier i) = do
     res1 <- discoverYADIS ident Nothing 10
     case res1 of
@@ -66,13 +61,10 @@
 
 -- | Attempt a YADIS based discovery, given a valid identifier.  The result is
 --   an OpenID endpoint, and the actual identifier for the user.
-discoverYADIS :: ( MonadIO m
-                 , Failure HttpException m
-                 )
-              => Identifier
+discoverYADIS :: Identifier
               -> Maybe String
               -> Int -- ^ remaining redirects
-              -> m (Maybe (Provider, Identifier, IdentType))
+              -> IO (Maybe (Provider, Identifier, IdentType))
 discoverYADIS _ _ 0 = failure TooManyRedirects
 discoverYADIS ident mb_loc redirects = do
     let uri = fromMaybe (unpack $ identifier ident) mb_loc
@@ -120,9 +112,7 @@
 
 -- | Attempt to discover an OpenID endpoint, from an HTML document.  The result
 -- will be an endpoint on success, and the actual identifier of the user.
-discoverHTML :: ( MonadIO m, Failure HttpException m)
-             => Identifier
-             -> m (Maybe Discovery)
+discoverHTML :: Identifier -> IO (Maybe Discovery)
 discoverHTML ident'@(Identifier ident) =
     (parseHTML ident' . toStrict . decodeUtf8With lenientDecode) `liftM` simpleHttp (unpack ident)
 
diff --git a/Web/Authenticate/BrowserId.hs b/Web/Authenticate/BrowserId.hs
--- a/Web/Authenticate/BrowserId.hs
+++ b/Web/Authenticate/BrowserId.hs
@@ -1,19 +1,14 @@
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE CPP #-}
 module Web.Authenticate.BrowserId
     ( browserIdJs
     , checkAssertion
     ) where
 
 import Data.Text (Text)
-import Network.HTTP.Enumerator (parseUrl, responseBody, httpLbs, withManager, method, urlEncodedBody)
+import Network.HTTP.Conduit (parseUrl, responseBody, httpLbs, withManager, method, urlEncodedBody)
 import Data.Aeson (json, Value (Object, String))
 import Data.Attoparsec.Lazy (parse, maybeResult)
-#if MIN_VERSION_aeson(0, 4, 0)
 import qualified Data.HashMap.Lazy as Map
-#else
-import qualified Data.Map as Map
-#endif
 import Data.Text.Encoding (encodeUtf8)
 
 -- | Location of the Javascript file hosted by browserid.org
diff --git a/Web/Authenticate/Facebook.hs b/Web/Authenticate/Facebook.hs
--- a/Web/Authenticate/Facebook.hs
+++ b/Web/Authenticate/Facebook.hs
@@ -13,7 +13,7 @@
     , getLogoutUrl
     ) where
 
-import Network.HTTP.Enumerator
+import Network.HTTP.Conduit
 import Network.HTTP.Types (parseSimpleQuery)
 import Data.Aeson
 import qualified Data.ByteString.Lazy.Char8 as L8
diff --git a/Web/Authenticate/OAuth.hs b/Web/Authenticate/OAuth.hs
--- a/Web/Authenticate/OAuth.hs
+++ b/Web/Authenticate/OAuth.hs
@@ -16,7 +16,7 @@
       -- * Utility Methods
       paramEncode, addScope, addMaybeProxy
     ) where
-import Network.HTTP.Enumerator
+import Network.HTTP.Conduit
 import Data.Data
 import qualified Data.ByteString.Char8 as BS
 import qualified Data.ByteString.Lazy.Char8 as BSL
@@ -36,11 +36,12 @@
 import Network.HTTP.Types (Header)
 import Control.Arrow (second)
 import Blaze.ByteString.Builder (toByteString)
-import Data.Enumerator (($$), run_, Stream (..), continue)
-import Data.Monoid (mconcat)
-import Control.Monad.IO.Class (MonadIO (liftIO))
-import Data.IORef (newIORef, readIORef, atomicModifyIORef)
+import Control.Monad.IO.Class (MonadIO)
 import Network.HTTP.Types (renderSimpleQuery)
+import Data.Conduit (ResourceIO, runResourceT, ($$), ($=), Source)
+import qualified Data.Conduit.List as CL
+import Data.Conduit.Blaze (builderToByteString)
+import Blaze.ByteString.Builder (Builder)
 
 -- | Data type for OAuth client (consumer).
 data OAuth = OAuth { oauthServerName      :: String        -- ^ Service name
@@ -226,7 +227,7 @@
             , ("oauth_version", "1.0")
             ] cred
 
-genSign :: MonadIO m => OAuth -> Credential -> Request m -> m BS.ByteString
+genSign :: ResourceIO m => OAuth -> Credential -> Request m -> m BS.ByteString
 genSign oa tok req =
   case oauthSignatureMethod oa of
     HMACSHA1 -> do
@@ -254,7 +255,7 @@
                                oct = '%' : replicate (2 - length num) '0' ++ num
                            in BS.pack oct
 
-getBaseString :: MonadIO m => Credential -> Request m -> m BSL.ByteString
+getBaseString :: ResourceIO m => Credential -> Request m -> m BSL.ByteString
 getBaseString tok req = do
   let bsMtd  = BS.map toUpper $ method req
       isHttps = secure req
@@ -274,23 +275,15 @@
   -- So this is OK.
   return $ BSL.intercalate "&" $ map (fromStrict.paramEncode) [bsMtd, bsURI, bsParams]
 
-toLBS :: MonadIO m => RequestBody m -> m BS.ByteString
+toLBS :: ResourceIO m => RequestBody m -> m BS.ByteString
 toLBS (RequestBodyLBS l) = return $ toStrict l
 toLBS (RequestBodyBS s) = return s
 toLBS (RequestBodyBuilder _ b) = return $ toByteString b
-toLBS (RequestBodyEnum _ enum) = do
-    i <- liftIO $ newIORef id
-    run_ $ enum $$ go i
-    liftIO $ liftM (toByteString . mconcat . ($ [])) $ readIORef i
-  where
-    go i =
-        continue go'
-      where
-        go' (Chunks []) = continue go'
-        go' (Chunks x) = do
-            liftIO (atomicModifyIORef i $ \y -> (y . (x ++), ()))
-            continue go'
-        go' EOF = return ()
+toLBS (RequestBodySource _ src) = toLBS' src
+toLBS (RequestBodySourceChunked src) = toLBS' src
+
+toLBS' :: ResourceIO m => Source m Builder -> m BS.ByteString
+toLBS' src = fmap BS.concat $ runResourceT $ src $= builderToByteString $$ CL.consume
 
 isBodyFormEncoded :: [Header] -> Bool
 isBodyFormEncoded = maybe False (=="application/x-www-form-urlencoded") . lookup "Content-Type"
diff --git a/Web/Authenticate/OpenId.hs b/Web/Authenticate/OpenId.hs
--- a/Web/Authenticate/OpenId.hs
+++ b/Web/Authenticate/OpenId.hs
@@ -16,7 +16,7 @@
 import Data.Text.Lazy.Encoding (decodeUtf8With)
 import Data.Text.Encoding.Error (lenientDecode)
 import Data.Text.Lazy (toStrict)
-import Network.HTTP.Enumerator
+import Network.HTTP.Conduit
     ( parseUrl, urlEncodedBody, responseBody, httpLbsRedirect
     , HttpException, withManager
     )
@@ -41,7 +41,7 @@
     -> m Text -- ^ URL to send the user to.
 getForwardUrl openid' complete mrealm params = do
     let realm = fromMaybe complete mrealm
-    disc <- normalize openid' >>= discover
+    disc <- liftIO $ normalize openid' >>= discover
     let helper s q = return $ s `mappend` decodeUtf8 (toByteString $ renderQueryText True $ map (second Just) q)
     case disc of
         Discovery1 server mdelegate -> helper server
@@ -86,7 +86,7 @@
                 Just i -> return i
                 Nothing ->
                     failure $ AuthenticationException "Missing identity"
-    disc <- normalize ident >>= discover
+    disc <- liftIO $ normalize ident >>= discover
     let endpoint = case disc of
                     Discovery1 p _ -> p
                     Discovery2 (Provider p) _ _ -> p
diff --git a/Web/Authenticate/Rpxnow.hs b/Web/Authenticate/Rpxnow.hs
--- a/Web/Authenticate/Rpxnow.hs
+++ b/Web/Authenticate/Rpxnow.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE PackageImports #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 ---------------------------------------------------------
@@ -23,8 +22,8 @@
     ) where
 
 import Data.Aeson
-import Network.HTTP.Enumerator
-import "transformers" Control.Monad.IO.Class
+import Network.HTTP.Conduit
+import Control.Monad.IO.Class
 import Control.Failure
 import Data.Maybe
 import Control.Monad
diff --git a/authenticate.cabal b/authenticate.cabal
--- a/authenticate.cabal
+++ b/authenticate.cabal
@@ -1,5 +1,5 @@
 name:            authenticate
-version:         0.10.4
+version:         0.11.0
 license:         BSD3
 license-file:    LICENSE
 author:          Michael Snoyman, Hiromi Ishii, Arash Rouhani
@@ -15,8 +15,8 @@
 
 library
     build-depends:   base >= 4 && < 5,
-                     aeson >= 0.3.2.11,
-                     http-enumerator >= 0.6.5.4 && < 0.8,
+                     aeson >= 0.5,
+                     http-conduit >= 1.0 && < 1.1,
                      tagsoup >= 0.12 && < 0.13,
                      failure >= 0.0.0 && < 0.2,
                      transformers >= 0.1 && < 0.3,
@@ -30,14 +30,15 @@
                      random >= 1.0 && < 1.1,
                      text >= 0.5 && < 1.0,
                      http-types >= 0.6 && < 0.7,
-                     enumerator >= 0.4.7 && < 0.5,
-                     xml-enumerator >= 0.4 && < 0.5,
+                     xml-conduit >= 0.5 && < 0.6,
                      blaze-builder >= 0.2 && < 0.4,
                      attoparsec >= 0.9,
                      tls >= 0.7 && < 0.9,
                      containers,
                      unordered-containers,
-                     process >= 1.0.1.1 && < 1.2
+                     process >= 1.0.1.1 && < 1.2,
+                     conduit >= 0.0 && < 0.1,
+                     blaze-builder-conduit >= 0.0 && < 0.1
     exposed-modules: Web.Authenticate.Rpxnow,
                      Web.Authenticate.OpenId,
                      Web.Authenticate.BrowserId,