diff --git a/mix.exs b/mix.exs
index 52d1b40..755de30 100644
--- a/mix.exs
+++ b/mix.exs
@@ -33,10 +33,19 @@ defmodule ExTwitter.Mixfile do
   def application do
     [
       mod: {ExTwitter, []},
-      applications: [:inets, :ssl, :crypto, :logger, :oauther]
+      applications: [:inets, :ssl, :crypto, :logger, :oauther, :jason],
+      extra_applications: extra_applications(Mix.env())
     ]
   end
 
+  defp extra_applications(:test), do: common_extra_applications()
+  defp extra_applications(:dev), do: common_extra_applications()
+  defp extra_applications(_), do: []
+
+  defp common_extra_applications do
+    [:exvcr, :mock]
+  end
+
   def deps do
     [
       {:oauther, "~> 1.3"},
@@ -44,7 +53,7 @@ defmodule ExTwitter.Mixfile do
       {:exvcr, "~> 0.14", only: :test},
       {:excoveralls, "~> 0.14", only: :test},
       {:meck, "~> 0.8.13", only: [:dev, :test]},
-      {:mock, "~> 0.2", only: [:dev, :test]},
+      {:mock, "~> 0.3", only: [:dev, :test]},
       {:ex_doc, ">= 0.0.0", only: [:dev, :docs], runtime: false},
       {:inch_ex, "~> 2.0", only: :docs},
       {:benchfella, "~> 0.3.3", only: :dev}
diff --git a/mix.lock b/mix.lock
index 61c441c..2e7c698 100644
--- a/mix.lock
+++ b/mix.lock
@@ -24,6 +24,6 @@
   "nimble_parsec": {:hex, :nimble_parsec, "1.2.0", "b44d75e2a6542dcb6acf5d71c32c74ca88960421b6874777f79153bbbbd7dccc", [:mix], [], "hexpm", "52b2871a7515a5ac49b00f214e4165a40724cf99798d8e4a65e4fd64ebd002c1"},
   "oauther": {:hex, :oauther, "1.3.0", "82b399607f0ca9d01c640438b34d74ebd9e4acd716508f868e864537ecdb1f76", [:mix], [], "hexpm", "78eb888ea875c72ca27b0864a6f550bc6ee84f2eeca37b093d3d833fbcaec04e"},
   "parse_trans": {:hex, :parse_trans, "3.3.1", "16328ab840cc09919bd10dab29e431da3af9e9e7e7e6f0089dd5a2d2820011d8", [:rebar3], [], "hexpm", "07cd9577885f56362d414e8c4c4e6bdf10d43a8767abb92d24cbe8b24c54888b"},
-  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.6", "cf344f5692c82d2cd7554f5ec8fd961548d4fd09e7d22f5b62482e5aeaebd4b0", [:make, :mix, :rebar3], [], "hexpm", "bdb0d2471f453c88ff3908e7686f86f9be327d065cc1ec16fa4540197ea04680"},
+  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.7", "354c321cf377240c7b8716899e182ce4890c5938111a1296add3ec74cf1715df", [:make, :mix, :rebar3], [], "hexpm", "fe4c190e8f37401d30167c8c405eda19469f34577987c76dde613e838bbc67f8"},
   "unicode_util_compat": {:hex, :unicode_util_compat, "0.7.0", "bc84380c9ab48177092f43ac89e4dfa2c6d62b40b8bd132b1059ecc7232f9a78", [:rebar3], [], "hexpm", "25eee6d67df61960cf6a794239566599b09e17e668d3700247bc498638152521"},
 }