diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+0.1.2.1
+=======
+
+* Compatibility with hoauth2-1.3.0 - fixed: [#4](https://github.com/fpco/wai-middleware-auth/issues/4)
+
 0.1.2.0
 =======
 
diff --git a/src/Network/Wai/Middleware/Auth/OAuth2.hs b/src/Network/Wai/Middleware/Auth/OAuth2.hs
--- a/src/Network/Wai/Middleware/Auth/OAuth2.hs
+++ b/src/Network/Wai/Middleware/Auth/OAuth2.hs
@@ -15,6 +15,7 @@
                                                        deriveJSON,
                                                        fieldLabelModifier)
 import qualified Data.ByteString                      as S
+import qualified Data.ByteString.Char8                as S8 (pack)
 import qualified Data.ByteString.Lazy                 as SL
 import           Data.Monoid                          ((<>))
 import           Data.Proxy                           (Proxy (..))
@@ -157,7 +158,7 @@
                man <- getGlobalManager
                eRes <- OA2.fetchAccessToken man oauth2 $ getExchangeToken code
                case eRes of
-                 Left err    -> onFailure status501 $ SL.toStrict err
+                 Left err    -> onFailure status501 $ S8.pack $ show err
                  Right token -> onSuccess $ getAccessToken token
              _ ->
                case lookup "error" params of
diff --git a/wai-middleware-auth.cabal b/wai-middleware-auth.cabal
--- a/wai-middleware-auth.cabal
+++ b/wai-middleware-auth.cabal
@@ -1,5 +1,5 @@
 name:                wai-middleware-auth
-version:             0.1.2.0
+version:             0.1.2.1
 synopsis:            Authentication middleware that secures WAI application
 description:         See README
 license:             MIT