diff --git a/app/controllers/admin/domain_blocks_controller.rb b/app/controllers/admin/domain_blocks_controller.rb
index 96c31a38fdf..325b33df80b 100644
--- a/app/controllers/admin/domain_blocks_controller.rb
+++ b/app/controllers/admin/domain_blocks_controller.rb
@@ -33,7 +33,7 @@ module Admin
 
       # Disallow accidentally downgrading a domain block
       if existing_domain_block.present? && !@domain_block.stricter_than?(existing_domain_block)
-        @domain_block.save
+        @domain_block.validate
         flash.now[:alert] = I18n.t('admin.domain_blocks.existing_domain_block_html', name: existing_domain_block.domain, unblock_url: admin_domain_block_path(existing_domain_block)).html_safe
         @domain_block.errors.delete(:domain)
         return render :new
diff --git a/spec/features/admin/domain_blocks_spec.rb b/spec/features/admin/domain_blocks_spec.rb
index 0d7b90c21cd..4379ac91dba 100644
--- a/spec/features/admin/domain_blocks_spec.rb
+++ b/spec/features/admin/domain_blocks_spec.rb
@@ -4,6 +4,7 @@ require 'rails_helper'
 
 describe 'blocking domains through the moderation interface' do
   before do
+    allow(DomainBlockWorker).to receive(:perform_async).and_return(true)
     sign_in Fabricate(:user, role: UserRole.find_by(name: 'Admin')), scope: :user
   end
 
@@ -16,6 +17,7 @@ describe 'blocking domains through the moderation interface' do
       click_button I18n.t('admin.domain_blocks.new.create')
 
       expect(DomainBlock.exists?(domain: 'example.com', severity: 'silence')).to be true
+      expect(DomainBlockWorker).to have_received(:perform_async)
     end
   end
 
@@ -27,13 +29,15 @@ describe 'blocking domains through the moderation interface' do
       select I18n.t('admin.domain_blocks.new.severity.suspend'), from: 'domain_block_severity'
       click_button I18n.t('admin.domain_blocks.new.create')
 
-      # It presents a confirmation screen
+      # It doesn't immediately block but presents a confirmation screen
       expect(page).to have_title(I18n.t('admin.domain_blocks.confirm_suspension.title', domain: 'example.com'))
+      expect(DomainBlockWorker).to_not have_received(:perform_async)
 
       # Confirming creates a block
       click_button I18n.t('admin.domain_blocks.confirm_suspension.confirm')
 
       expect(DomainBlock.exists?(domain: 'example.com', severity: 'suspend')).to be true
+      expect(DomainBlockWorker).to have_received(:perform_async)
     end
   end
 
@@ -47,13 +51,15 @@ describe 'blocking domains through the moderation interface' do
       select I18n.t('admin.domain_blocks.new.severity.suspend'), from: 'domain_block_severity'
       click_button I18n.t('admin.domain_blocks.new.create')
 
-      # It presents a confirmation screen
+      # It doesn't immediately block but presents a confirmation screen
       expect(page).to have_title(I18n.t('admin.domain_blocks.confirm_suspension.title', domain: 'example.com'))
+      expect(DomainBlockWorker).to_not have_received(:perform_async)
 
       # Confirming updates the block
       click_button I18n.t('admin.domain_blocks.confirm_suspension.confirm')
 
       expect(domain_block.reload.severity).to eq 'suspend'
+      expect(DomainBlockWorker).to have_received(:perform_async)
     end
   end
 
@@ -67,13 +73,15 @@ describe 'blocking domains through the moderation interface' do
       select I18n.t('admin.domain_blocks.new.severity.suspend'), from: 'domain_block_severity'
       click_button I18n.t('admin.domain_blocks.new.create')
 
-      # It presents a confirmation screen
+      # It doesn't immediately block but presents a confirmation screen
       expect(page).to have_title(I18n.t('admin.domain_blocks.confirm_suspension.title', domain: 'subdomain.example.com'))
+      expect(DomainBlockWorker).to_not have_received(:perform_async)
 
       # Confirming creates the block
       click_button I18n.t('admin.domain_blocks.confirm_suspension.confirm')
 
       expect(DomainBlock.where(domain: 'subdomain.example.com', severity: 'suspend')).to exist
+      expect(DomainBlockWorker).to have_received(:perform_async)
 
       # And leaves the previous block alone
       expect(domain_block.reload.severity).to eq 'silence'
@@ -90,11 +98,13 @@ describe 'blocking domains through the moderation interface' do
       select I18n.t('admin.domain_blocks.new.severity.suspend'), from: 'domain_block_severity'
       click_button I18n.t('generic.save_changes')
 
-      # It presents a confirmation screen
+      # It doesn't immediately block but presents a confirmation screen
       expect(page).to have_title(I18n.t('admin.domain_blocks.confirm_suspension.title', domain: 'example.com'))
+      expect(DomainBlockWorker).to_not have_received(:perform_async)
 
       # Confirming updates the block
       click_button I18n.t('admin.domain_blocks.confirm_suspension.confirm')
+      expect(DomainBlockWorker).to have_received(:perform_async)
 
       expect(domain_block.reload.severity).to eq 'suspend'
     end