diff --git a/.travis.yml b/.travis.yml
index 92e8bcda1..6d24ba65f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,6 +7,7 @@ script:
 
 addons:
   chrome: stable
+  postgresql: 9.4
 
 env:
   - DB=mysql
@@ -23,16 +24,27 @@ gemfile:
   - gemfiles/spree_3_2.gemfile
   - gemfiles/spree_3_5.gemfile
   - gemfiles/spree_3_7.gemfile
+  - gemfiles/spree_4_0.gemfile
   - gemfiles/spree_master.gemfile
 
 matrix:
     allow_failures:
       - gemfile: gemfiles/spree_master.gemfile
     exclude:
-    - rvm: 2.3.7
-      gemfile: gemfiles/spree_master.gemfile
-    - rvm: 2.4.4
-      gemfile: gemfiles/spree_master.gemfile
+      - rvm: 2.3.7
+        gemfile: gemfiles/spree_4_0.gemfile
+      - rvm: 2.4.4
+        gemfile: gemfiles/spree_4_0.gemfile
+      - rvm: 2.3.7
+        gemfile: gemfiles/spree_master.gemfile
+      - rvm: 2.4.4
+        gemfile: gemfiles/spree_master.gemfile
+      - rvm: 2.5.1
+        gemfile: gemfiles/spree_3_2.gemfile
+      - rvm: 2.5.1
+        gemfile: gemfiles/spree_3_2.gemfile
+      - rvm: 2.5.1
+        gemfile: gemfiles/spree_3_5.gemfile
 
 before_install:
   - mysql -u root -e "GRANT ALL ON *.* TO 'travis'@'%';"
diff --git a/Appraisals b/Appraisals
index f78972844..c79d6c5ff 100644
--- a/Appraisals
+++ b/Appraisals
@@ -9,10 +9,16 @@ appraise 'spree-3-5' do
 end
 
 appraise 'spree-3-7' do
+  gem 'sass-rails'
   gem 'spree', '~> 3.7.0.rc3'
   gem 'rails-controller-testing'
 end
 
+appraise 'spree-4-0' do
+  gem 'spree', github: 'spree/spree', tag: 'v4.0.0.beta'
+  gem 'rails-controller-testing'
+end
+
 appraise 'spree-master' do
   gem 'spree', github: 'spree/spree', branch: 'master'
   gem 'rails-controller-testing'
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 5497f82d1..a42a94b9d 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -41,6 +41,7 @@ en:
     user_registrations:
       destroyed: Bye! Your account was successfully cancelled. We hope to see you again soon.
       inactive_signed_up: 'You have signed up successfully. However, we could not sign you in because your account is %{reason}.'
+      signed_up_but_unconfirmed: You have signed up successfully.
       signed_up: Welcome! You have signed up successfully.
       updated: You updated your account successfully.
     user_sessions:
diff --git a/gemfiles/spree_3_7.gemfile b/gemfiles/spree_3_7.gemfile
index 168d586aa..746d9979d 100644
--- a/gemfiles/spree_3_7.gemfile
+++ b/gemfiles/spree_3_7.gemfile
@@ -4,5 +4,6 @@ source "https://rubygems.org"
 
 gem "rails-controller-testing"
 gem "spree", "~> 3.7.0.rc3"
+gem "sass-rails"
 
 gemspec path: "../"
diff --git a/gemfiles/spree_4_0.gemfile b/gemfiles/spree_4_0.gemfile
new file mode 100644
index 000000000..88447dd28
--- /dev/null
+++ b/gemfiles/spree_4_0.gemfile
@@ -0,0 +1,8 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "rails-controller-testing"
+gem "spree", github: "spree/spree", tag: "v4.0.0.beta"
+
+gemspec path: "../"
diff --git a/lib/controllers/backend/spree/admin/admin_resource_controller_decorator.rb b/lib/controllers/backend/spree/admin/admin_resource_controller_decorator.rb
deleted file mode 100644
index aa90216cc..000000000
--- a/lib/controllers/backend/spree/admin/admin_resource_controller_decorator.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-Spree::Admin::ResourceController.class_eval do
-  rescue_from CanCan::AccessDenied, with: :unauthorized
-end
diff --git a/lib/controllers/backend/spree/admin/admin_controller_decorator.rb b/lib/controllers/backend/spree/admin/base_controller_decorator.rb
similarity index 86%
rename from lib/controllers/backend/spree/admin/admin_controller_decorator.rb
rename to lib/controllers/backend/spree/admin/base_controller_decorator.rb
index d9a72ea3f..c69c433fb 100644
--- a/lib/controllers/backend/spree/admin/admin_controller_decorator.rb
+++ b/lib/controllers/backend/spree/admin/base_controller_decorator.rb
@@ -1,4 +1,4 @@
-Spree::Admin::BaseController.class_eval do
+module Spree::Admin::BaseControllerDecorator
   # Redirect as appropriate when an access request fails.  The default action is to redirect to the login screen.
   # Override this method in your controllers if you want to have special behavior in case the user is not authorized
   # to access the requested action.  For example, a popup window might simply close itself.
@@ -22,3 +22,4 @@ def model_class
     nil
   end
 end
+Spree::Admin::BaseController.prepend(Spree::Admin::BaseControllerDecorator)
diff --git a/lib/controllers/backend/spree/admin/orders/customer_details_controller_decorator.rb b/lib/controllers/backend/spree/admin/orders/customer_details_controller_decorator.rb
index 9caef0641..ca6876149 100644
--- a/lib/controllers/backend/spree/admin/orders/customer_details_controller_decorator.rb
+++ b/lib/controllers/backend/spree/admin/orders/customer_details_controller_decorator.rb
@@ -1,5 +1,8 @@
-Spree::Admin::Orders::CustomerDetailsController.class_eval do
-  before_action :check_authorization
+module Spree::Admin::Orders::CustomerDetailsControllerDecorator
+
+  def self.prepended(base)
+    base.before_action :check_authorization
+  end
 
   private
 
@@ -14,3 +17,4 @@ def check_authorization
     authorize! action, resource, session[:access_token]
   end
 end
+Spree::Admin::Orders::CustomerDetailsController.prepend(Spree::Admin::Orders::CustomerDetailsControllerDecorator)
diff --git a/lib/controllers/backend/spree/admin/admin_orders_controller_decorator.rb b/lib/controllers/backend/spree/admin/orders_controller_decorator.rb
similarity index 70%
rename from lib/controllers/backend/spree/admin/admin_orders_controller_decorator.rb
rename to lib/controllers/backend/spree/admin/orders_controller_decorator.rb
index e938b77d6..989627c4c 100644
--- a/lib/controllers/backend/spree/admin/admin_orders_controller_decorator.rb
+++ b/lib/controllers/backend/spree/admin/orders_controller_decorator.rb
@@ -1,5 +1,8 @@
-Spree::Admin::OrdersController.class_eval do
-  before_action :check_authorization
+module Spree::Admin::OrdersControllerDecorator
+
+  def self.prepended(base)
+    base.before_action :check_authorization
+  end
 
   private
 
@@ -19,3 +22,4 @@ def check_authorization
     end
   end
 end
+Spree::Admin::OrdersController.prepend(Spree::Admin::OrdersControllerDecorator)
diff --git a/lib/controllers/backend/spree/admin/resource_controller_decorator.rb b/lib/controllers/backend/spree/admin/resource_controller_decorator.rb
new file mode 100644
index 000000000..839129f32
--- /dev/null
+++ b/lib/controllers/backend/spree/admin/resource_controller_decorator.rb
@@ -0,0 +1,6 @@
+module Spree::Admin::ResourceControllerDecorator
+  def self.prepended(base)
+    base.rescue_from CanCan::AccessDenied, with: :unauthorized
+  end
+end
+Spree::Admin::ResourceController.prepend(Spree::Admin::ResourceControllerDecorator)
diff --git a/lib/controllers/frontend/spree/checkout_controller_decorator.rb b/lib/controllers/frontend/spree/checkout_controller_decorator.rb
index 17d69ffae..8a56d60bd 100644
--- a/lib/controllers/frontend/spree/checkout_controller_decorator.rb
+++ b/lib/controllers/frontend/spree/checkout_controller_decorator.rb
@@ -1,7 +1,9 @@
 require 'spree/core/validators/email' if Spree.version.to_f < 3.5
-Spree::CheckoutController.class_eval do
-  before_action :check_authorization
-  before_action :check_registration, except: [:registration, :update_registration]
+module Spree::CheckoutControllerDecorator
+  def self.prepended(base)
+    base.before_action :check_authorization
+    base.before_action :check_registration, except: [:registration, :update_registration]
+  end
 
   def registration
     @user = Spree::User.new
@@ -39,3 +41,4 @@ def check_registration
     redirect_to spree.checkout_registration_path
   end
 end
+Spree::CheckoutController.prepend(Spree::CheckoutControllerDecorator)
diff --git a/lib/controllers/frontend/spree/store_controller_decorator.rb b/lib/controllers/frontend/spree/store_controller_decorator.rb
index 9bbc1752b..4de98ab13 100644
--- a/lib/controllers/frontend/spree/store_controller_decorator.rb
+++ b/lib/controllers/frontend/spree/store_controller_decorator.rb
@@ -1,6 +1,7 @@
-Spree::StoreController.class_eval do
+module Spree::StoreControllerDecorator
   def account_link
     render partial: 'spree/shared/link_to_account'
     fresh_when(spree_current_user)
   end
 end
+Spree::StoreController.prepend(Spree::StoreControllerDecorator)
diff --git a/spec/features/checkout_spec.rb b/spec/features/checkout_spec.rb
index 9a671fb54..1156687fe 100644
--- a/spec/features/checkout_spec.rb
+++ b/spec/features/checkout_spec.rb
@@ -133,11 +133,10 @@
 
       expect(page).to have_text 'Registration'
 
-      fill_in 'Email', with: 'email@person.com'
+      fill_in 'Email', with: 'email@person.com', match: :first
       fill_in 'Password', with: 'spree123'
       fill_in 'Password Confirmation', with: 'spree123'
       click_button 'Create'
-
       expect(page).to have_text 'You have signed up successfully.'
 
       str_addr = 'bill_address'
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 5e5d5d586..9258f0c47 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -22,6 +22,12 @@
 
   config.order = :random
   Kernel.srand(config.seed)
+
+  config.before(:each) do
+    allow(RSpec::Rails::ViewRendering::EmptyTemplateHandler)
+      .to receive(:call)
+      .and_return(%("")) if Rails.gem_version >= Gem::Version.new('6.0.0.beta1')
+  end
 end
 
 Dir[File.join(File.dirname(__FILE__), 'support/**/*.rb')].each { |f| require f }
diff --git a/spree_auth_devise.gemspec b/spree_auth_devise.gemspec
index 1e86da6fc..f7d35eacb 100644
--- a/spree_auth_devise.gemspec
+++ b/spree_auth_devise.gemspec
@@ -3,7 +3,7 @@
 Gem::Specification.new do |s|
   s.platform    = Gem::Platform::RUBY
   s.name        = 'spree_auth_devise'
-  s.version     = '4.0.0.beta'
+  s.version     = '4.0.0.rc1'
   s.summary     = 'Provides authentication and authorization services for use with Spree by using Devise and CanCan.'
   s.description = s.summary
 
@@ -19,7 +19,7 @@ Gem::Specification.new do |s|
   s.require_path = 'lib'
   s.requirements << 'none'
 
-  s.add_dependency 'devise', '>= 4.4', '< 4.7'
+  s.add_dependency 'devise', '~> 4.7'
   s.add_dependency 'devise-encryptable', '0.2.0'
 
   spree_version = '>= 3.1.0', '< 5.0'