diff --git a/postmark.cabal b/postmark.cabal
--- a/postmark.cabal
+++ b/postmark.cabal
@@ -1,5 +1,5 @@
 Name:               postmark
-Version:            0.1.1
+Version:            0.2.0
 License:            BSD3
 License-File:       LICENSE
 Author:             Mark Hibberd <mark@hibberd.id.au>
@@ -11,6 +11,7 @@
 Bug-reports:        https://github.com/apiengine/postmark/issues
 Cabal-Version:      >= 1.8
 Build-Type:         Simple
+Tested-With:        GHC == 7.10.3, GHC == 8.0.2
 Description:
   postmark
 
@@ -27,15 +28,15 @@
 
 Library
   Build-Depends:
-                    base                            >= 3          && < 5
-                    , aeson                         >= 0.6
-                    , attoparsec                    >= 0.10
-                    , bytestring                    >= 0.9
-                    , containers                    >= 0.4
-                    , http-types                    >= 0.6
-                    , text                          >= 0.11
-                    , network-api-support           >= 0.1.0
-                    , http-client-tls               >= 0.2.1.1
+                    base                            >= 3 && < 5
+                    , aeson                         >= 0.6 && < 1.3
+                    , attoparsec                    >= 0.10 && < 0.14
+                    , bytestring                    >= 0.9 && < 0.11
+                    , containers                    >= 0.4 && < 0.6
+                    , http-types                    >= 0.6 && < 1
+                    , text                          >= 0.11 && < 1.3
+                    , network-api-support           >= 0.3.0 && < 0.4
+                    , http-client-tls               >= 0.2.1.1 && < 0.4
 
 
   GHC-Options:
@@ -53,6 +54,7 @@
                     Network.Api.Postmark.Response
                     Network.Api.Postmark.Settings
                     Network.Api.Postmark.Tutorial
+
 
 executable         postmark-demo
     if flag(demo)
diff --git a/src/Network/Api/Postmark/Data.hs b/src/Network/Api/Postmark/Data.hs
--- a/src/Network/Api/Postmark/Data.hs
+++ b/src/Network/Api/Postmark/Data.hs
@@ -1,8 +1,6 @@
 {-# LANGUAGE OverloadedStrings, GADTSyntax #-}
 module Network.Api.Postmark.Data where
 
-import Control.Applicative
-
 import qualified Data.ByteString.Lazy as BL
 import qualified Data.Text.Lazy as LT
 import qualified Data.Text.Lazy.Encoding as LE
diff --git a/src/Network/Api/Postmark/Error.hs b/src/Network/Api/Postmark/Error.hs
--- a/src/Network/Api/Postmark/Error.hs
+++ b/src/Network/Api/Postmark/Error.hs
@@ -1,8 +1,6 @@
 {-# LANGUAGE OverloadedStrings, GADTSyntax #-}
 module Network.Api.Postmark.Error where
 
-import Control.Applicative
-
 import Data.Aeson
 import Data.Text