diff --git a/mix.exs b/mix.exs
index 17680a1..ad3da82 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,38 +1,38 @@
 defmodule KolabWopi.Mixfile do
   use Mix.Project
 
   def project do
     [
       app: :kolab_wopi,
       description: "Kolab REST API implementing Web Application Open Interface",
       version: "0.0.1",
       elixir: "~> 1.2",
       build_embedded: Mix.env == :prod,
       start_permanent: Mix.env == :prod,
       deps: deps
     ]
   end
 
   # Configuration for the OTP application
   #
   # Type "mix help compile.app" for more information
   def application do
     [
       applications: [:logger, :cowboy, :plug, :httpoison],
       mod: {KolabWopi, []}
     ]
   end
 
   # Dependencies can be Hex packages:
   #
   # Type "mix help deps" for more examples and options
   defp deps do
     [
       {:cowboy, "~> 1.0"},
       {:plug, "~> 1.3.2"},
       {:httpoison, "~> 0.9"},
       {:poison, "~> 2.2"},
-      {:credo, "~> 0.4.12", only: [:dev, :test]}
+      {:credo, "~> 0.5", only: [:dev, :test]}
     ]
   end
 end
diff --git a/mix.lock b/mix.lock
index 28d13bf..ff05c26 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,15 +1,15 @@
 %{"bunt": {:hex, :bunt, "0.1.6", "5d95a6882f73f3b9969fdfd1953798046664e6f77ec4e486e6fafc7caad97c6f", [:mix], []},
   "certifi": {:hex, :certifi, "0.4.0", "a7966efb868b179023618d29a407548f70c52466bf1849b9e8ebd0e34b7ea11f", [:rebar3], []},
   "cowboy": {:hex, :cowboy, "1.0.4", "a324a8df9f2316c833a470d918aaf73ae894278b8aa6226ce7a9bf699388f878", [:rebar, :make], [{:cowlib, "~> 1.0.0", [hex: :cowlib, optional: false]}, {:ranch, "~> 1.0", [hex: :ranch, optional: false]}]},
   "cowlib": {:hex, :cowlib, "1.0.2", "9d769a1d062c9c3ac753096f868ca121e2730b9a377de23dec0f7e08b1df84ee", [:make], []},
-  "credo": {:hex, :credo, "0.4.12", "f5e1973405ea25c6e64959fb0b6bf92950147a0278cc2a002a491b45f78f7b87", [:mix], [{:bunt, "~> 0.1.6", [hex: :bunt, optional: false]}]},
+  "credo": {:hex, :credo, "0.5.3", "0c405b36e7651245a8ed63c09e2d52c2e2b89b6d02b1570c4d611e0fcbecf4a2", [:mix], [{:bunt, "~> 0.1.6", [hex: :bunt, optional: false]}]},
   "hackney": {:hex, :hackney, "1.6.1", "ddd22d42db2b50e6a155439c8811b8f6df61a4395de10509714ad2751c6da817", [:rebar3], [{:certifi, "0.4.0", [hex: :certifi, optional: false]}, {:idna, "1.2.0", [hex: :idna, optional: false]}, {:metrics, "1.0.1", [hex: :metrics, optional: false]}, {:mimerl, "1.0.2", [hex: :mimerl, optional: false]}, {:ssl_verify_fun, "1.1.0", [hex: :ssl_verify_fun, optional: false]}]},
   "httpoison": {:hex, :httpoison, "0.9.1", "6c2b4eaf2588a6f3ef29663d28c992531ca3f0bc832a97e0359bc822978e1c5d", [:mix], [{:hackney, "~> 1.6.0", [hex: :hackney, optional: false]}]},
   "idna": {:hex, :idna, "1.2.0", "ac62ee99da068f43c50dc69acf700e03a62a348360126260e87f2b54eced86b2", [:rebar3], []},
   "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], []},
   "mime": {:hex, :mime, "1.0.1", "05c393850524767d13a53627df71beeebb016205eb43bfbd92d14d24ec7a1b51", [:mix], []},
   "mimerl": {:hex, :mimerl, "1.0.2", "993f9b0e084083405ed8252b99460c4f0563e41729ab42d9074fd5e52439be88", [:rebar3], []},
   "plug": {:hex, :plug, "1.3.2", "8391d8ba2e2c187de069211110a882599e851f64550c556163b5130e1e2dbc1b", [:mix], [{:cowboy, "~> 1.0.1 or ~> 1.1", [hex: :cowboy, optional: true]}, {:mime, "~> 1.0", [hex: :mime, optional: false]}]},
   "poison": {:hex, :poison, "2.2.0", "4763b69a8a77bd77d26f477d196428b741261a761257ff1cf92753a0d4d24a63", [:mix], []},
   "ranch": {:hex, :ranch, "1.2.1", "a6fb992c10f2187b46ffd17ce398ddf8a54f691b81768f9ef5f461ea7e28c762", [:make], []},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.0", "edee20847c42e379bf91261db474ffbe373f8acb56e9079acb6038d4e0bf414f", [:rebar, :make], []}}