diff --git a/mix.exs b/mix.exs
index 6975d33..4f3b41b 100644
--- a/mix.exs
+++ b/mix.exs
@@ -7,7 +7,7 @@ defmodule HTTPoison.Mixfile do
 
   def project do
     [ app: :httpoison,
-      version: "0.3.3",
+      version: "0.4.0",
       elixir: "~> 0.15.0",
       name: "HTTPoison",
       description: @description,