diff --git a/.travis.yml b/.travis.yml
index f1b202b..5f2b450 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,6 @@
 language: elixir
 
 elixir:
-  - 1.4
   - 1.5
   - 1.6
   - 1.7
@@ -20,12 +19,10 @@ matrix:
       otp_release: 19.3
     - elixir: 1.8
       otp_release: 19.3
-    - elixir: 1.4
-      otp_release: 21
     - elixir: 1.5
-      otp_release: 21
+      otp_release: 21.0
     - elixir: 1.6
-      otp_release: 21
+      otp_release: 21.0
 
 before_script:
   - "export DISPLAY=:99.0"
diff --git a/lib/hound/connection_server.ex b/lib/hound/connection_server.ex
index 8d9c2ff..5db405c 100644
--- a/lib/hound/connection_server.ex
+++ b/lib/hound/connection_server.ex
@@ -1,5 +1,6 @@
 defmodule Hound.ConnectionServer do
   @moduledoc false
+  use Agent
 
   def start_link(options \\ []) do
     driver = options[:driver] || Application.get_env(:hound, :driver, "selenium")
diff --git a/lib/hound/session_server.ex b/lib/hound/session_server.ex
index c8de347..1bf6e42 100644
--- a/lib/hound/session_server.ex
+++ b/lib/hound/session_server.ex
@@ -4,7 +4,7 @@ defmodule Hound.SessionServer do
   use GenServer
   @name __MODULE__
 
-  def start_link do
+  def start_link(_options) do
     GenServer.start_link(__MODULE__, %{}, name: @name)
   end
 
diff --git a/lib/hound/supervisor.ex b/lib/hound/supervisor.ex
index 0ba3ca3..9927847 100644
--- a/lib/hound/supervisor.ex
+++ b/lib/hound/supervisor.ex
@@ -4,18 +4,18 @@ defmodule Hound.Supervisor do
   use Supervisor
 
   def start_link(options \\ []) do
-    :supervisor.start_link(__MODULE__, [options])
+    Supervisor.start_link(__MODULE__, options, name: __MODULE__)
   end
 
-
-  def init([options]) do
+  @impl true
+  def init(options) do
     children = [
-      worker(Hound.ConnectionServer, [options]),
-      worker(Hound.SessionServer, [])
+      {Hound.ConnectionServer, options},
+      Hound.SessionServer
     ]
 
-    # See http://elixir-lang.org/docs/stable/Supervisor.Behaviour.html
+    # See https://hexdocs.pm/elixir/master/Supervisor.html#content
     # for other strategies and supported options
-    supervise(children, strategy: :one_for_one)
+    Supervisor.init(children, strategy: :one_for_one)
   end
 end
diff --git a/mix.exs b/mix.exs
index 4831a49..d5590b6 100644
--- a/mix.exs
+++ b/mix.exs
@@ -6,7 +6,7 @@ defmodule Hound.Mixfile do
   def project do
     [ app: :hound,
       version: @version,
-      elixir: ">= 1.4.0",
+      elixir: ">= 1.5.0",
       description: "Webdriver library for integration testing and browser automation",
       source_url: "https://github.com/HashNuke/hound",
       deps: deps(),