diff --git a/Web/Authenticate/BrowserId.hs b/Web/Authenticate/BrowserId.hs
--- a/Web/Authenticate/BrowserId.hs
+++ b/Web/Authenticate/BrowserId.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE CPP #-}
 module Web.Authenticate.BrowserId
     ( browserIdJs
     , checkAssertion
@@ -8,7 +9,11 @@
 import Network.HTTP.Enumerator (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/Rpxnow.hs b/Web/Authenticate/Rpxnow.hs
--- a/Web/Authenticate/Rpxnow.hs
+++ b/Web/Authenticate/Rpxnow.hs
@@ -38,7 +38,11 @@
 import qualified Data.Attoparsec.Lazy as AT
 import Data.Text (Text)
 import qualified Data.Aeson.Types
+#if MIN_VERSION_aeson(0, 4, 0)
+import qualified Data.HashMap.Lazy as Map
+#else
 import qualified Data.Map as Map
+#endif
 import Control.Applicative ((<$>), (<*>))
 
 -- | Information received from Rpxnow after a valid login.
diff --git a/authenticate.cabal b/authenticate.cabal
--- a/authenticate.cabal
+++ b/authenticate.cabal
@@ -1,5 +1,5 @@
 name:            authenticate
-version:         0.10.3
+version:         0.10.3.1
 license:         BSD3
 license-file:    LICENSE
 author:          Michael Snoyman, Hiromi Ishii, Arash Rouhani
@@ -36,6 +36,7 @@
                      attoparsec >= 0.9,
                      tls >= 0.7 && < 0.9,
                      containers,
+                     unordered-containers,
                      process >= 1.0.1.1 && < 1.2
     exposed-modules: Web.Authenticate.Rpxnow,
                      Web.Authenticate.OpenId,