diff --git a/Gemfile b/Gemfile
index 7c62a122..d1466712 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,9 @@
 source 'https://rubygems.org'
+
+group :test, :remote_test do
+  gem 'pry-rails'
+end
+
 gemspec
 
 gem 'jruby-openssl', :platforms => :jruby
diff --git a/activemerchant.gemspec b/activemerchant.gemspec
index 5c322135..e17fe676 100644
--- a/activemerchant.gemspec
+++ b/activemerchant.gemspec
@@ -14,7 +14,7 @@ Gem::Specification.new do |s|
   s.homepage = 'http://activemerchant.org/'
   s.rubyforge_project = 'activemerchant'
 
-  s.required_ruby_version = '>= 2'
+  s.required_ruby_version = '>= 2.3'
 
   s.files = Dir['CHANGELOG', 'README.md', 'MIT-LICENSE', 'CONTRIBUTORS', 'lib/**/*', 'vendor/**/*']
   s.require_path = 'lib'
@@ -30,4 +30,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency('test-unit', '~> 3')
   s.add_development_dependency('mocha', '~> 1')
   s.add_development_dependency('thor')
+  s.add_development_dependency('shopify_api', '~> 4.0')
 end
diff --git a/lib/active_merchant/billing/gateways/shopify.rb b/lib/active_merchant/billing/gateways/shopify.rb
new file mode 100644
index 00000000..4117870d
--- /dev/null
+++ b/lib/active_merchant/billing/gateways/shopify.rb
@@ -0,0 +1,134 @@
+require 'shopify_api'
+
+module ActiveMerchant #:nodoc:
+  module Billing #:nodoc:
+    class ShopifyGateway < Gateway
+      class TransactionNotFoundError < Error; end
+      class CreditedAmountBiggerThanTransaction < Error; end
+
+      self.homepage_url = 'https://shopify.ca/'
+      self.display_name = 'Shopify'
+
+      def initialize(options = {})
+        requires!(options, :api_key)
+        requires!(options, :password)
+        requires!(options, :shop_name)
+
+        @api_key = options[:api_key]
+        @password = options[:password]
+        @shop_name = options[:shop_name]
+
+        init_shopify_api!
+
+        super
+      end
+
+      def void(transaction_id, options = {})
+        order_id = options[:order_id]
+        voider = ShopifyVoider.new(transaction_id, order_id)
+        voider.perform
+      end
+
+      def refund(money, transaction_id, options = {})
+        refunder = ShopifyRefunder.new(money, transaction_id, options)
+        refunder.perform
+      end
+
+      private
+
+      attr_reader :api_key, :password, :shop_name
+
+      def init_shopify_api!
+        ::ShopifyAPI::Base.site = shop_url
+      end
+
+      def shop_url
+        "https://#{api_key}:#{password}@#{shop_name}"
+      end
+    end
+  end
+end
+
+class ShopifyVoider
+  def initialize(transaction_id, order_id)
+    @order_id = order_id
+    @transaction = ::ShopifyAPI::Transaction.find(transaction_id, params: { order_id: order_id })
+  end
+
+  def perform
+    raise ActiveMerchant::Billing::ShopifyGateway::TransactionNotFoundError if transaction.nil?
+
+    options = { order_id: order_id, reason: 'Payment voided' }
+    full_amount_to_cents = BigDecimal.new(transaction.amount) * 100
+    refunder = ShopifyRefunder.new(full_amount_to_cents, transaction.id, options)
+    refunder.perform
+  end
+
+  private
+
+  attr_reader :transaction, :order_id
+end
+
+class ShopifyRefunder
+  def initialize(credited_money, transaction_id, options)
+    @refund_reason = options[:reason]
+    @order_id = options[:order_id]
+    @credited_money = BigDecimal.new(credited_money)
+    @transaction = ::ShopifyAPI::Transaction.find(transaction_id, params: { order_id: order_id })
+  end
+
+  def perform
+    raise ActiveMerchant::Billing::ShopifyGateway::TransactionNotFoundError if transaction.nil?
+
+    # NOTE(cab): This should be refactored when we are sure that this is the
+    # behavior we want
+    if full_refund?
+      perform_refund_on_shopify
+    elsif partial_refund?
+      perform_refund_on_shopify
+    else
+      raise ActiveMerchant::Billing::ShopifyGateway::CreditedAmountBiggerThanTransaction
+    end
+  end
+
+  private
+
+  def perform_refund_on_shopify
+    refund = ::ShopifyAPI::Refund.create(order_id: order_id,
+                                         shipping: { amount: 0 },
+                                         note: refund_reason,
+                                         notify: false,
+                                         restock: false,
+                                         transactions: [{
+                                           parent_id: transaction.id,
+                                           amount: amount_to_dollars(credited_money),
+                                           gateway: 'shopify-payments',
+                                           kind: 'refund'
+                                         }])
+
+    success = refund.errors == []
+    if success || refund.errors.messages.empty?
+      ActiveMerchant::Billing::Response.new(true, nil)
+    else
+      ActiveMerchant::Billing::Response.new(success, refund.errors.messages)
+    end
+  end
+
+  def full_refund?
+    credited_money == amount_to_cents(transaction.amount)
+  end
+
+  def partial_refund?
+    credited_money < amount_to_cents(transaction.amount)
+  end
+
+  def amount_to_cents(amount)
+    BigDecimal.new(amount) * 100
+  end
+
+  def amount_to_dollars(amount)
+    BigDecimal.new(amount) / 100
+  end
+
+  attr_accessor :credited_money, :refund_reason, :transaction, :order_id
+end
diff --git a/test/fixtures.yml b/test/fixtures.yml
index 8586621d..51323f92 100644
--- a/test/fixtures.yml
+++ b/test/fixtures.yml
@@ -942,6 +942,12 @@ spreedly_core:
   password: "Y2i7AjgU03SUjwY4xnOPqzdsv4dMbPDCQzorAk8Bcoy0U8EIVE4innGjuoMQv7MN"
   gateway_token: "3gLeg4726V5P0HK7cq7QzHsL0a6"
 
+# Replace with your own credentials
+shopify:
+  api_key: "use"
+  password: "your"
+  shop_name: "own"
+
 # Working credentials, no need to replace
 stripe:
   login: sk_test_3OD4TdKSIOhDOL2146JJcC79
diff --git a/test/test_helper.rb b/test/test_helper.rb
index c80e72c3..0a89ff09 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -11,6 +11,8 @@
 require 'active_merchant'
 require 'comm_stub'
 
+require 'pry'
+
 require 'active_support/core_ext/integer/time'
 require 'active_support/core_ext/numeric/time'
 require 'active_support/core_ext/time/acts_like'
diff --git a/test/unit/gateways/remote_shopify_test.rb b/test/unit/gateways/remote_shopify_test.rb
new file mode 100644
index 00000000..8db61e7b
--- /dev/null
+++ b/test/unit/gateways/remote_shopify_test.rb
@@ -0,0 +1,87 @@
+require 'test_helper'
+
+class RemoteStripeTest < Test::Unit::TestCase
+  def setup
+    @gateway = ShopifyGateway.new(fixtures(:shopify))
+
+    @refund_amount = 50
+    @refund_amount_in_cents = @refund_amount * 100
+    @order = create_fulfilled_paid_shopify_order
+    @transaction = ::ShopifyAPI::Order.find(@order.id).transactions.first
+
+    @refund_options = { order_id: @order.id, reason: 'Object is malfunctioning' }
+    @void_options = { order_id: @order.id, reason: 'Payment voided' }
+  end
+
+  def teardown
+    @order.destroy
+  end
+
+  def test_successful_void
+    assert response = @gateway.void(@transaction.id, @void_options)
+    assert_success response
+  end
+
+  def test_successful_full_refund
+    assert response = @gateway.refund(@refund_amount_in_cents, @transaction.id, @refund_options)
+    assert_success response
+  end
+
+  def test_successful_partial_refund
+    assert response = @gateway.refund(@refund_amount_in_cents / 2, @transaction.id, @refund_options)
+    assert_success response
+  end
+
+  private
+
+  def create_fulfilled_paid_shopify_order
+    order = ::ShopifyAPI::Order.new
+    order.email = 'cab@godynamo.com'
+    order.test = true
+    order.fulfillment_status = 'fulfilled'
+    order.line_items = [
+      {
+        variant_id: '447654529',
+        quantity: 1,
+        name: 'test',
+        price: @refund_amount,
+        title: 'title'
+      }
+    ]
+    order.customer = { first_name: 'Paul',
+                       last_name: 'Norman',
+                       email: 'paul.norman@example.com' }
+
+    order.billing_address = {
+      first_name: 'John',
+      last_name: 'Smith',
+      address1: '123 Fake Street',
+      phone: '555-555-5555',
+      city: 'Fakecity',
+      province: 'Ontario',
+      country: 'Canada',
+      zip: 'K2P 1L4'
+    }
+    order.shipping_address = {
+      first_name: 'John',
+      last_name: 'Smith',
+      address1: '123 Fake Street',
+      phone: '555-555-5555',
+      city: 'Fakecity',
+      province: 'Ontario',
+      country: 'Canada',
+      zip: 'K2P 1L4'
+    }
+    order.transactions = [
+      {
+        kind: 'capture',
+        status: 'success',
+        amount: @refund_amount
+      }
+    ]
+    order.financial_status = 'paid'
+    order.save
+
+    order
+  end
+end
diff --git a/test/unit/gateways/shopify_test.rb b/test/unit/gateways/shopify_test.rb
new file mode 100644
index 00000000..f9bb5e34
--- /dev/null
+++ b/test/unit/gateways/shopify_test.rb
@@ -0,0 +1,55 @@
+require 'test_helper'
+
+class ShopifyTest < Test::Unit::TestCase
+  def setup
+    @gateway = ShopifyGateway.new(api_key: 'api_key',
+                                  password: 'password',
+                                  shop_name: 'shop_name')
+  end
+
+  def test_void_calls_refund
+    transaction_id = 123
+    transaction = stub(amount: 1, id: transaction_id)
+    refunder_instance = stub(perform: true)
+    ::ShopifyAPI::Transaction.expects(:find).returns(transaction)
+    ShopifyRefunder.expects(:new).returns(refunder_instance)
+
+    refunder_instance.expects(:perform).once
+    @gateway.void(123, { order_id: '123' })
+  end
+
+  def test_void_with_not_found_transaction
+    ::ShopifyAPI::Transaction.expects(:find).returns(nil)
+    assert_raises(::ActiveMerchant::Billing::ShopifyGateway::TransactionNotFoundError) { @gateway.void(123, order_id: '123') }
+  end
+
+  def test_refund_with_not_found_transaction
+    ::ShopifyAPI::Transaction.expects(:find).returns(nil)
+    assert_raises(::ActiveMerchant::Billing::ShopifyGateway::TransactionNotFoundError) { @gateway.refund(123, 123, { order_id: '123', reason: 'reason' }) }
+  end
+
+  def test_refund_with_credit_to_big
+    transaction = stub(amount: 1)
+    ::ShopifyAPI::Transaction.stubs(:find).returns(transaction)
+    assert_raises(::ActiveMerchant::Billing::ShopifyGateway::CreditedAmountBiggerThanTransaction) { @gateway.refund(10000, 123, { order_id: '123', reason: 'reason' }) }
+  end
+
+  def test_response_value_of_unsuccessful_refund
+    transaction_id = 123
+    transaction = stub(amount: 1, id: transaction_id)
+    refund = stub(errors: [])
+    ::ShopifyAPI::Transaction.stubs(:find).returns(transaction)
+    ::ShopifyAPI::Refund.stubs(:create).returns(refund)
+    assert_success(@gateway.refund(100, transaction_id, { order_id: '123', reason: 'reason' }))
+  end
+
+  def test_reponse_value_of_successful_refund
+    transaction_id = 123
+    transaction = stub(amount: 1, id: transaction_id)
+    errors = stub(messages: { error: 'error1' })
+    refund = stub(errors: errors)
+    ::ShopifyAPI::Transaction.stubs(:find).returns(transaction)
+    ::ShopifyAPI::Refund.stubs(:create).returns(refund)
+    assert_failure(@gateway.refund(100, transaction_id, { order_id: '123', reason: 'reason' }))
+  end
+end