diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
 # giphy-api
 [![Build Status](https://travis-ci.org/passy/giphy-api.svg?branch=master)](https://travis-ci.org/passy/giphy-api)
 [![Hackage](http://img.shields.io/hackage/v/giphy-api.svg)](https://hackage.haskell.org/package/giphy-api)
-[![Stackage 6](http://stackage.org/package/giphy-api/badge/lts-6)](http://stackage.org/lts-6/package/giphy-api)
-[![Stackage 7](http://stackage.org/package/giphy-api/badge/lts-7)](http://stackage.org/lts-7/package/giphy-api)
+[![Stackage 8](http://stackage.org/package/giphy-api/badge/lts-8)](http://stackage.org/lts-8/package/giphy-api)
+[![Stackage 9](http://stackage.org/package/giphy-api/badge/lts-9)](http://stackage.org/lts-9/package/giphy-api)
 [![Stackage Nightly](http://stackage.org/package/giphy-api/badge/nightly)](http://stackage.org/nightly/package/giphy-api)
 
 
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## v0.6.0.0
+
+- Upgrade to Servant 0.13.
+
 ## v0.5.2.0
 
 - Fix #12: Compilation error with base 4.7
diff --git a/giphy-api.cabal b/giphy-api.cabal
--- a/giphy-api.cabal
+++ b/giphy-api.cabal
@@ -1,9 +1,11 @@
--- This file has been generated from package.yaml by hpack version 0.15.0.
+-- This file has been generated from package.yaml by hpack version 0.20.0.
 --
 -- see: https://github.com/sol/hpack
+--
+-- hash: 2890c2a27640ed634840dd8de9c65df6d456f44b7ee11432111658ce7e93a390
 
 name:           giphy-api
-version:        0.5.2.0
+version:        0.6.0.0
 synopsis:       Giphy HTTP API wrapper and CLI search tool.
 description:    Please see README.md
 category:       Web
@@ -31,22 +33,22 @@
 library
   hs-source-dirs:
       src
-  ghc-options: -Wall -fwarn-tabs -fwarn-incomplete-record-updates -fwarn-monomorphism-restriction -fwarn-unused-do-bind
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-uni-patterns -Wincomplete-record-updates -Wmonomorphism-restriction
   build-depends:
-      base >= 4.7 && < 5
-    , text
-    , network-uri
-    , aeson
+      aeson
+    , base >=4.7 && <5
     , containers
+    , http-api-data
+    , http-client
+    , http-client-tls
     , microlens
     , microlens-th
     , mtl
-    , servant >= 0.9
-    , servant-client >= 0.9
+    , network-uri
+    , servant >=0.13
+    , servant-client >=0.9
+    , text
     , transformers
-    , http-api-data
-    , http-client
-    , http-client-tls
   exposed-modules:
       Web.Giphy
   other-modules:
@@ -57,11 +59,11 @@
   main-is: Main.hs
   hs-source-dirs:
       app
-  ghc-options: -Wall -fwarn-tabs -fwarn-incomplete-record-updates -fwarn-monomorphism-restriction -fwarn-unused-do-bind -threaded -rtsopts -with-rtsopts=-N
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-uni-patterns -Wincomplete-record-updates -Wmonomorphism-restriction -threaded -rtsopts -with-rtsopts=-N
   build-depends:
-      base >= 4.7 && < 5
-    , text
+      base >=4.7 && <5
     , network-uri
+    , text
   if flag(buildSample)
     build-depends:
         giphy-api
@@ -71,6 +73,7 @@
     buildable: False
   other-modules:
       Sample
+      Paths_giphy_api
   default-language: Haskell2010
 
 test-suite spec
@@ -78,17 +81,19 @@
   main-is: Spec.hs
   hs-source-dirs:
       test
-  ghc-options: -Wall -fwarn-tabs -fwarn-incomplete-record-updates -fwarn-monomorphism-restriction -fwarn-unused-do-bind -threaded -rtsopts -with-rtsopts=-N
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-uni-patterns -Wincomplete-record-updates -Wmonomorphism-restriction -threaded -rtsopts -with-rtsopts=-N
   build-depends:
-      base >= 4.7 && < 5
-    , text
-    , network-uri
-    , giphy-api
-    , aeson
+      aeson
+    , base >=4.7 && <5
     , basic-prelude
     , bytestring
     , containers
     , directory
+    , giphy-api
     , hspec
     , lens
+    , network-uri
+    , text
+  other-modules:
+      Paths_giphy_api
   default-language: Haskell2010
diff --git a/src/Web/Giphy.hs b/src/Web/Giphy.hs
--- a/src/Web/Giphy.hs
+++ b/src/Web/Giphy.hs
@@ -424,7 +424,7 @@
   -> GiphyConfig
   -> m (Either Servant.ServantError a)
 runGiphy' manager giphy conf =
-  let env = Servant.ClientEnv manager baseUrl
+  let env = Servant.ClientEnv manager baseUrl Nothing
       runClientM' = flip Servant.runClientM
   in
       liftIO . runClientM' env . Reader.runReaderT giphy $ GiphyContext conf
diff --git a/stack.yaml b/stack.yaml
--- a/stack.yaml
+++ b/stack.yaml
@@ -2,4 +2,4 @@
 extra-package-dbs: []
 packages:
 - '.'
-resolver: nightly-2016-11-24
+resolver: lts-11.1
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -32,7 +32,8 @@
 
       it "parses a search response" $ do
         resp <- readFixture "search_response.json"
-        let res = either error id (Aeson.eitherDecode resp)
+        let res :: Giphy.SearchResponse
+            res = either error id (Aeson.eitherDecode resp)
         let item = res ^?! Giphy.searchItems . _head
 
         item ^. Giphy.gifId `shouldBe` "QgcQLZa6glP2w"