diff --git a/Gemfile b/Gemfile
index 955ab8f..14ec6a5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,8 +1,7 @@
-ENV['rails'] ||= '4.2.0'
-
 source 'https://rubygems.org'
 
 # use Rails version specified by environment
+ENV['rails'] ||= '4.2.0'
 gem 'rails', "~> #{ENV['rails']}"
 
 gemspec
diff --git a/bin/console b/bin/console
new file mode 100755
index 0000000..68067dd
--- /dev/null
+++ b/bin/console
@@ -0,0 +1,9 @@
+#!/usr/bin/env ruby
+
+require 'bundler/setup'
+Bundler.require :default
+
+require 'doorkeeper/openid_connect'
+
+require 'pry'
+Pry.start
diff --git a/bin/setup b/bin/setup
new file mode 100755
index 0000000..dce67d8
--- /dev/null
+++ b/bin/setup
@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+set -euo pipefail
+IFS=$'\n\t'
+set -vx
+
+bundle install
+
+# Do any other automated setup that you need to do here
diff --git a/doorkeeper-openid_connect.gemspec b/doorkeeper-openid_connect.gemspec
index a2bceed..c847571 100644
--- a/doorkeeper-openid_connect.gemspec
+++ b/doorkeeper-openid_connect.gemspec
@@ -18,7 +18,10 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
+  spec.required_ruby_version = ">= 2.1"
+
   spec.add_runtime_dependency 'doorkeeper', '~> 4.0'
+  #spec.add_runtime_dependency 'activemodel', '~> 4.0'
   spec.add_runtime_dependency 'json-jwt', '~> 1.6.5'
 
   spec.add_development_dependency 'rspec-rails'
diff --git a/lib/doorkeeper/openid_connect.rb b/lib/doorkeeper/openid_connect.rb
index c9f2b91..ef48c3f 100644
--- a/lib/doorkeeper/openid_connect.rb
+++ b/lib/doorkeeper/openid_connect.rb
@@ -1,4 +1,5 @@
 require 'doorkeeper'
+require 'active_model'
 require 'json/jwt'
 
 require 'doorkeeper/openid_connect/claims_builder'