diff --git a/app/models/user.rb b/app/models/user.rb
index 8e0785e7fdd..21e1898bdb2 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -137,6 +137,8 @@ class User < ApplicationRecord
   attribute :external, :boolean, default: false
   attribute :bypass_registration_checks, :boolean, default: false
 
+  class_attribute :skip_mx_check, default: Rails.env.local?
+
   def self.those_who_can(*any_of_privileges)
     matching_role_ids = UserRole.that_can(*any_of_privileges).map(&:id)
 
@@ -147,10 +149,6 @@ class User < ApplicationRecord
     end
   end
 
-  def self.skip_mx_check?
-    Rails.env.local?
-  end
-
   def date_of_birth=(hash_or_string)
     @date_of_birth = begin
       if hash_or_string.is_a?(Hash)
diff --git a/spec/controllers/auth/registrations_controller_spec.rb b/spec/controllers/auth/registrations_controller_spec.rb
index a110717166d..388aa475328 100644
--- a/spec/controllers/auth/registrations_controller_spec.rb
+++ b/spec/controllers/auth/registrations_controller_spec.rb
@@ -228,7 +228,7 @@ RSpec.describe Auth::RegistrationsController do
       end
     end
 
-    context 'when user has an email address requiring approval through a MX record' do
+    context 'when user has an email address requiring approval through a MX record', :enable_mx_checks do
       subject do
         request.headers['Accept-Language'] = accept_language
         post :create, params: { user: { account_attributes: { username: 'test' }, email: 'test@example.com', password: '12345678', password_confirmation: '12345678', agreement: 'true' } }
@@ -237,7 +237,6 @@ RSpec.describe Auth::RegistrationsController do
       before do
         Setting.registrations_mode = 'open'
         Fabricate(:email_domain_block, allow_with_approval: true, domain: 'mail.example.com')
-        allow(User).to receive(:skip_mx_check?).and_return(false)
         configure_mx(domain: 'example.com', exchange: 'mail.example.com')
       end
 
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index 3d3e556f353..4fbe65a96d3 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -139,6 +139,12 @@ RSpec.configure do |config|
     example.run
   end
 
+  config.around(:each, :enable_mx_checks) do |example|
+    User.skip_mx_check = false
+    example.run
+    User.skip_mx_check = true
+  end
+
   config.around(:each, type: :search) do |example|
     Chewy.settings[:enabled] = true
     example.run
diff --git a/spec/services/app_sign_up_service_spec.rb b/spec/services/app_sign_up_service_spec.rb
index b78868db494..3401c4f227b 100644
--- a/spec/services/app_sign_up_service_spec.rb
+++ b/spec/services/app_sign_up_service_spec.rb
@@ -48,11 +48,10 @@ RSpec.describe AppSignUpService do
       end
     end
 
-    context 'when the email address requires approval through MX records' do
+    context 'when the email address requires approval through MX records', :enable_mx_checks do
       before do
         Setting.registrations_mode = 'open'
         Fabricate(:email_domain_block, allow_with_approval: true, domain: 'smtp.email.com')
-        allow(User).to receive(:skip_mx_check?).and_return(false)
         configure_mx(domain: 'email.com', exchange: 'smtp.email.com')
       end