diff --git a/google-translate.cabal b/google-translate.cabal
--- a/google-translate.cabal
+++ b/google-translate.cabal
@@ -1,11 +1,11 @@
 name:                google-translate
-version:             0.4.1
+version:             0.5
 synopsis:            Google Translate API bindings
 license:             BSD3
 license-file:        LICENSE
 author:              David Johnson, Dmitry Dzhus
 maintainer:          djohnson.m@gmail.com
-copyright:           David Johnson (c) 2016
+copyright:           David Johnson (c) 2018
 category:            Web
 build-type:          Simple
 cabal-version:       >=1.10
@@ -24,8 +24,8 @@
                      , transformers   >= 0.4 && < 0.6
                      , http-api-data  >= 0.2 && < 0.4
                      , http-client    >= 0.4 && < 0.6
-                     , servant        >= 0.7 && < 0.12
-                     , servant-client >= 0.7 && < 0.12
+                     , servant        >= 0.13
+                     , servant-client >= 0.13
                      , text           == 1.2.*
   default-language:    Haskell2010
 
diff --git a/src/Web/Google/Translate.hs b/src/Web/Google/Translate.hs
--- a/src/Web/Google/Translate.hs
+++ b/src/Web/Google/Translate.hs
@@ -9,7 +9,7 @@
 ------------------------------------------------------------------------------
 -- |
 -- Module      : Web.Google.Translate
--- Copyright   : (c) David Johnson 2016
+-- Copyright   : (c) David Johnson 2018
 -- Maintainer  : djohnson.m@gmail.com
 -- Stability   : experimental
 -- Portability : POSIX
@@ -212,7 +212,7 @@
   -> IO (Either ServantError DetectionResponse)
 detect mgr key body =
   runClientM (detect' (Just key) (Just body))
-             (ClientEnv mgr googleApis)
+             (ClientEnv mgr googleApis Nothing)
 ------------------------------------------------------------------------------
 -- | Perform translation from `Source` language to `Target` langauge.
 -- If `Source` not specified, attempt detection of `Lang`
@@ -225,7 +225,7 @@
   -> IO (Either ServantError TranslationResponse)
 translate mgr key src trgt body =
   runClientM (translate' (Just key) src (Just trgt) (Just body))
-             (ClientEnv mgr googleApis)
+             (ClientEnv mgr googleApis Nothing)
 ------------------------------------------------------------------------------
 -- | Retrieve all languages
 -- If `Target` specified, return langauge name in `Target` langauge.
@@ -236,7 +236,7 @@
   -> IO (Either ServantError LanguageResponse)
 getLanguages mgr key trgt =
   runClientM (getLanguages' (Just key) trgt)
-             (ClientEnv mgr googleApis)
+             (ClientEnv mgr googleApis Nothing)
 ------------------------------------------------------------------------------
 instance Show Lang where
   show Afrikaans          = "af"