diff --git a/lib/omniauth/strategies/oauth2.rb b/lib/omniauth/strategies/oauth2.rb
deleted file mode 100644
index 3ffff1b..0000000
--- a/lib/omniauth/strategies/oauth2.rb
+++ /dev/null
@@ -1,127 +0,0 @@
-require "oauth2"
-require "omniauth"
-require "securerandom"
-require "socket"       # for SocketError
-require "timeout"      # for Timeout::Error
-
-module OmniAuth
-  module Strategies
-    # Authentication strategy for connecting with APIs constructed using
-    # the [OAuth 2.0 Specification](http://tools.ietf.org/html/draft-ietf-oauth-v2-10).
-    # You must generally register your application with the provider and
-    # utilize an application id and secret in order to authenticate using
-    # OAuth 2.0.
-    class OAuth2
-      include OmniAuth::Strategy
-
-      def self.inherited(subclass)
-        OmniAuth::Strategy.included(subclass)
-      end
-
-      args [:client_id, :client_secret]
-
-      option :client_id, nil
-      option :client_secret, nil
-      option :client_options, {}
-      option :authorize_params, {}
-      option :authorize_options, [:scope]
-      option :token_params, {}
-      option :token_options, []
-      option :auth_token_params, {}
-      option :provider_ignores_state, false
-
-      attr_accessor :access_token
-
-      def client
-        ::OAuth2::Client.new(options.client_id, options.client_secret, deep_symbolize(options.client_options))
-      end
-
-      credentials do
-        hash = {"token" => access_token.token}
-        hash.merge!("refresh_token" => access_token.refresh_token) if access_token.expires? && access_token.refresh_token
-        hash.merge!("expires_at" => access_token.expires_at) if access_token.expires?
-        hash.merge!("expires" => access_token.expires?)
-        hash
-      end
-
-      def request_phase
-        redirect client.auth_code.authorize_url({:redirect_uri => callback_url}.merge(authorize_params))
-      end
-
-      def authorize_params
-        options.authorize_params[:state] = SecureRandom.hex(24)
-        params = options.authorize_params.merge(options_for("authorize"))
-        if OmniAuth.config.test_mode
-          @env ||= {}
-          @env["rack.session"] ||= {}
-        end
-        session["omniauth.state"] = params[:state]
-        params
-      end
-
-      def token_params
-        options.token_params.merge(options_for("token"))
-      end
-
-      def callback_phase # rubocop:disable AbcSize, CyclomaticComplexity, MethodLength, PerceivedComplexity
-        error = request.params["error_reason"] || request.params["error"]
-        if error
-          fail!(error, CallbackError.new(request.params["error"], request.params["error_description"] || request.params["error_reason"], request.params["error_uri"]))
-        elsif !options.provider_ignores_state && (request.params["state"].to_s.empty? || request.params["state"] != session.delete("omniauth.state"))
-          fail!(:csrf_detected, CallbackError.new(:csrf_detected, "CSRF detected"))
-        else
-          self.access_token = build_access_token
-          self.access_token = access_token.refresh! if access_token.expired?
-          super
-        end
-      rescue ::OAuth2::Error, CallbackError => e
-        fail!(:invalid_credentials, e)
-      rescue ::Timeout::Error, ::Errno::ETIMEDOUT => e
-        fail!(:timeout, e)
-      rescue ::SocketError => e
-        fail!(:failed_to_connect, e)
-      end
-
-    protected
-
-      def build_access_token
-        verifier = request.params["code"]
-        client.auth_code.get_token(verifier, {:redirect_uri => callback_url}.merge(token_params.to_hash(:symbolize_keys => true)), deep_symbolize(options.auth_token_params))
-      end
-
-      def deep_symbolize(options)
-        hash = {}
-        options.each do |key, value|
-          hash[key.to_sym] = value.is_a?(Hash) ? deep_symbolize(value) : value
-        end
-        hash
-      end
-
-      def options_for(option)
-        hash = {}
-        options.send(:"#{option}_options").select { |key| options[key] }.each do |key|
-          hash[key.to_sym] = options[key]
-        end
-        hash
-      end
-
-      # An error that is indicated in the OAuth 2.0 callback.
-      # This could be a `redirect_uri_mismatch` or other
-      class CallbackError < StandardError
-        attr_accessor :error, :error_reason, :error_uri
-
-        def initialize(error, error_reason = nil, error_uri = nil)
-          self.error = error
-          self.error_reason = error_reason
-          self.error_uri = error_uri
-        end
-
-        def message
-          [error, error_reason, error_uri].compact.join(" | ")
-        end
-      end
-    end
-  end
-end
-
-OmniAuth.config.add_camelization "oauth2", "OAuth2"