diff --git a/spec/factories/user.rb b/spec/factories/user.rb
index 01d6b9583..8d2a53953 100644
--- a/spec/factories/user.rb
+++ b/spec/factories/user.rb
@@ -19,6 +19,10 @@ FactoryBot.define do
 
     factory :customer_user, aliases: %i[customer] do
       role_ids { Role.signup_role_ids.sort }
+
+      trait :with_org do
+        organization
+      end
     end
 
     factory :agent_user, aliases: %i[agent] do
diff --git a/spec/models/ticket_spec.rb b/spec/models/ticket_spec.rb
index 5cde81a00..a712fce2d 100644
--- a/spec/models/ticket_spec.rb
+++ b/spec/models/ticket_spec.rb
@@ -247,6 +247,42 @@ RSpec.describe Ticket, type: :model do
     end
   end
 
+  describe 'Associations:' do
+    describe '#organization' do
+      subject(:ticket) { build(:ticket, customer: customer, organization: nil) }
+      let(:customer) { create(:customer, :with_org) }
+
+      context 'on creation' do
+        it 'automatically adopts the organization of its #customer' do
+          expect { ticket.save }
+            .to change { ticket.organization }.to(customer.organization)
+        end
+      end
+
+      context 'on update of #customer.organization' do
+        context 'to nil' do
+          it 'automatically updates to #customer’s new value' do
+            ticket.save
+
+            expect { customer.update(organization: nil) }
+              .to change { ticket.reload.organization }.to(nil)
+          end
+        end
+
+        context 'to a different organization' do
+          let(:new_org) { create(:organization) }
+
+          it 'automatically updates to #customer’s new value' do
+            ticket.save
+
+            expect { customer.update(organization: new_org) }
+              .to change { ticket.reload.organization }.to(new_org)
+          end
+        end
+      end
+    end
+  end
+
   describe 'Callbacks & Observers -' do
     describe 'NULL byte handling (via ChecksAttributeValuesAndLength concern):' do
       it 'removes them from title on creation, if necessary (postgres doesn’t like them)' do
diff --git a/test/unit/ticket_customer_organization_update_test.rb b/test/unit/ticket_customer_organization_update_test.rb
deleted file mode 100644
index fbd985507..000000000
--- a/test/unit/ticket_customer_organization_update_test.rb
+++ /dev/null
@@ -1,77 +0,0 @@
-require 'test_helper'
-
-class TicketCustomerOrganizationUpdateTest < ActiveSupport::TestCase
-
-  setup do
-    groups = Group.where(name: 'Users')
-    roles  = Role.where(name: 'Agent')
-    @agent1 = User.create_or_update(
-      login:         'ticket-customer-organization-update-agent1@example.com',
-      firstname:     'Notification',
-      lastname:      'Agent1',
-      email:         'ticket-customer-organization-update-agent1@example.com',
-      password:      'agentpw',
-      active:        true,
-      roles:         roles,
-      groups:        groups,
-      updated_at:    '2015-02-05 16:37:00',
-      updated_by_id: 1,
-      created_by_id: 1,
-    )
-    roles = Role.where(name: 'Customer')
-    @organization1 = Organization.create_if_not_exists(
-      name:          'Customer Organization Update',
-      updated_at:    '2015-02-05 16:37:00',
-      updated_by_id: 1,
-      created_by_id: 1,
-    )
-    @customer1 = User.create_or_update(
-      login:           'ticket-customer-organization-update-customer1@example.com',
-      firstname:       'Notification',
-      lastname:        'Customer1',
-      email:           'ticket-customer-organization-update-customer1@example.com',
-      password:        'customerpw',
-      active:          true,
-      organization_id: @organization1.id,
-      roles:           roles,
-      updated_at:      '2015-02-05 16:37:00',
-      updated_by_id:   1,
-      created_by_id:   1,
-    )
-  end
-
-  test 'create ticket, update customers organization later' do
-
-    ticket = Ticket.create(
-      title:         "some title1\n äöüß",
-      group:         Group.lookup(name: 'Users'),
-      customer_id:   @customer1.id,
-      owner_id:      @agent1.id,
-      state:         Ticket::State.lookup(name: 'new'),
-      priority:      Ticket::Priority.lookup(name: '2 normal'),
-      updated_by_id: 1,
-      created_by_id: 1,
-    )
-    assert(ticket, 'ticket created')
-    assert_equal(@customer1.id, ticket.customer.id)
-    assert_equal(@organization1.id, ticket.organization.id)
-
-    # update customer organization
-    @customer1.organization_id = nil
-    @customer1.save!
-
-    # verify ticket
-    ticket.reload
-    assert_nil(ticket.organization_id)
-
-    # update customer organization
-    @customer1.organization_id = @organization1.id
-    @customer1.save!
-
-    # verify ticket
-    ticket.reload
-    assert_equal(@organization1.id, ticket.organization_id)
-
-    ticket.destroy
-  end
-end