diff --git a/Gemfile.lock b/Gemfile.lock
index bce39abb3..96e7408e3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -456,7 +456,7 @@ GEM
     rubocop-rails (2.3.2)
       rack (>= 1.1)
       rubocop (>= 0.72.0)
-    rubocop-rspec (1.33.0)
+    rubocop-rspec (1.35.0)
       rubocop (>= 0.60.0)
     ruby-progressbar (1.10.1)
     ruby-saml (1.10.2)
diff --git a/spec/jobs/search_index_job_spec.rb b/spec/jobs/search_index_job_spec.rb
index 2d037fb64..ee7c1463b 100644
--- a/spec/jobs/search_index_job_spec.rb
+++ b/spec/jobs/search_index_job_spec.rb
@@ -19,6 +19,6 @@ RSpec.describe SearchIndexJob, type: :job do
   it 'retries on exception' do
     expect(::User).to receive(:lookup).and_raise(RuntimeError)
     described_class.perform_now('User', 1)
-    expect(SearchIndexJob).to have_been_enqueued
+    expect(described_class).to have_been_enqueued
   end
 end
diff --git a/spec/jobs/ticket_online_notification_seen_job_spec.rb b/spec/jobs/ticket_online_notification_seen_job_spec.rb
index 1c9eb90ac..e6e1124be 100644
--- a/spec/jobs/ticket_online_notification_seen_job_spec.rb
+++ b/spec/jobs/ticket_online_notification_seen_job_spec.rb
@@ -17,7 +17,7 @@ RSpec.describe TicketOnlineNotificationSeenJob, type: :job do
     ticket.save!
 
     expect do
-      TicketOnlineNotificationSeenJob.perform_now(ticket.id, user.id)
+      described_class.perform_now(ticket.id, user.id)
     end.to change { online_notification.reload.seen }
   end
 end
diff --git a/spec/jobs/ticket_user_ticket_counter_job_spec.rb b/spec/jobs/ticket_user_ticket_counter_job_spec.rb
index 36d7db75a..094e0a0f7 100644
--- a/spec/jobs/ticket_user_ticket_counter_job_spec.rb
+++ b/spec/jobs/ticket_user_ticket_counter_job_spec.rb
@@ -30,7 +30,7 @@ RSpec.describe TicketUserTicketCounterJob, type: :job do
   end
 
   it 'checks if customer ticket count has been updated in preferences' do
-    TicketUserTicketCounterJob.perform_now(
+    described_class.perform_now(
       customer.id,
       customer.id,
     )
diff --git a/spec/lib/search_index_backend_spec.rb b/spec/lib/search_index_backend_spec.rb
index 0524597fc..2b12e60ba 100644
--- a/spec/lib/search_index_backend_spec.rb
+++ b/spec/lib/search_index_backend_spec.rb
@@ -110,7 +110,7 @@ RSpec.describe SearchIndexBackend, searchindex: true do
     context 'ticket' do
       it 'from index after ticket delete' do
 
-        skip('No ES configured') if !SearchIndexBackend.enabled?
+        skip('No ES configured') if !described_class.enabled?
 
         ticket = create :ticket
         described_class.add('Ticket', ticket)
diff --git a/spec/models/calendar_spec.rb b/spec/models/calendar_spec.rb
index abbce6972..9d1293370 100644
--- a/spec/models/calendar_spec.rb
+++ b/spec/models/calendar_spec.rb
@@ -5,14 +5,14 @@ RSpec.describe Calendar, type: :model do
 
   describe 'attributes' do
     describe '#default' do
-      before { expect(Calendar.pluck(:default)).to eq([true]) }
+      before { expect(described_class.pluck(:default)).to eq([true]) }
 
       context 'when set to true on creation' do
         subject(:calendar) { build(:calendar, default: true) }
 
         it 'stays true and sets all other calendars to default: false' do
           expect { calendar.tap(&:save).reload }.not_to change(calendar, :default)
-          expect(Calendar.where(default: true) - [calendar]).to be_empty
+          expect(described_class.where(default: true) - [calendar]).to be_empty
         end
       end
 
@@ -23,14 +23,14 @@ RSpec.describe Calendar, type: :model do
 
         it 'stays true and sets all other calendars to default: false' do
           expect { calendar.tap(&:save).reload }.not_to change(calendar, :default)
-          expect(Calendar.where(default: true) - [calendar]).to be_empty
+          expect(described_class.where(default: true) - [calendar]).to be_empty
         end
       end
 
       context 'when set to false on update' do
         it 'sets default: true on earliest-created calendar' do
-          expect { Calendar.first.update(default: false) }
-            .not_to change { Calendar.first.default }
+          expect { described_class.first.update(default: false) }
+            .not_to change { described_class.first.default }
         end
       end
 
@@ -38,7 +38,7 @@ RSpec.describe Calendar, type: :model do
         subject!(:calendar) { create(:calendar, default: false) }
 
         it 'sets default: true on earliest-created remaining calendar' do
-          expect { Calendar.first.destroy }
+          expect { described_class.first.destroy }
             .to change { calendar.reload.default }.to(true)
         end
       end
diff --git a/spec/models/channel/email_parser_spec.rb b/spec/models/channel/email_parser_spec.rb
index 733505af9..eae580e7c 100644
--- a/spec/models/channel/email_parser_spec.rb
+++ b/spec/models/channel/email_parser_spec.rb
@@ -40,7 +40,7 @@ RSpec.describe Channel::EmailParser, type: :model do
     describe 'auto-creating new users' do
       context 'with one unrecognized email address' do
         it 'creates one new user' do
-          expect { Channel::EmailParser.new.process({}, <<~RAW) }.to change(User, :count).by(1)
+          expect { described_class.new.process({}, <<~RAW) }.to change(User, :count).by(1)
             From: #{Faker::Internet.unique.email}
           RAW
         end
@@ -48,7 +48,7 @@ RSpec.describe Channel::EmailParser, type: :model do
 
       context 'with a large number of unrecognized recipient addresses' do
         it 'never creates more than 40 users' do
-          expect { Channel::EmailParser.new.process({}, <<~RAW) }.to change(User, :count).by(40)
+          expect { described_class.new.process({}, <<~RAW) }.to change(User, :count).by(40)
             From: nicole.braun@zammad.org
             To: #{Array.new(20) { Faker::Internet.unique.email }.join(', ')}
             Cc: #{Array.new(21) { Faker::Internet.unique.email }.join(', ')}
@@ -59,7 +59,7 @@ RSpec.describe Channel::EmailParser, type: :model do
 
     describe 'auto-updating existing users' do
       context 'with a previous email with no real name in the From: header' do
-        let!(:customer) { Channel::EmailParser.new.process({}, previous_email).first.customer }
+        let!(:customer) { described_class.new.process({}, previous_email).first.customer }
 
         let(:previous_email) { <<~RAW.chomp }
           From: customer@example.com
@@ -79,7 +79,7 @@ RSpec.describe Channel::EmailParser, type: :model do
           RAW
 
           it 'updates the customer’s #firstname and #lastname' do
-            expect { Channel::EmailParser.new.process({}, new_email) }
+            expect { described_class.new.process({}, new_email) }
               .to change { customer.reload.firstname }.from('').to('Max')
               .and change { customer.reload.lastname }.from('').to('Smith')
           end
@@ -98,19 +98,19 @@ RSpec.describe Channel::EmailParser, type: :model do
         RAW
 
         it 'creates a ticket and article' do
-          expect { Channel::EmailParser.new.process({}, raw_mail) }
+          expect { described_class.new.process({}, raw_mail) }
             .to change(Ticket, :count).by(1)
             .and change(Ticket::Article, :count).by_at_least(1)
         end
 
         it 'sets #title to email subject' do
-          Channel::EmailParser.new.process({}, raw_mail)
+          described_class.new.process({}, raw_mail)
 
           expect(Ticket.last.title).to eq('Foo')
         end
 
         it 'sets #state to "new"' do
-          Channel::EmailParser.new.process({}, raw_mail)
+          described_class.new.process({}, raw_mail)
 
           expect(Ticket.last.state.name).to eq('new')
         end
@@ -119,13 +119,13 @@ RSpec.describe Channel::EmailParser, type: :model do
           let!(:agent) { create(:agent_user, email: 'foo@bar.com') }
 
           it 'sets article.sender to "Agent"' do
-            Channel::EmailParser.new.process({}, raw_mail)
+            described_class.new.process({}, raw_mail)
 
             expect(Ticket::Article.last.sender.name).to eq('Agent')
           end
 
           it 'sets ticket.state to "new"' do
-            Channel::EmailParser.new.process({}, raw_mail)
+            described_class.new.process({}, raw_mail)
 
             expect(Ticket.last.state.name).to eq('new')
           end
@@ -135,13 +135,13 @@ RSpec.describe Channel::EmailParser, type: :model do
           let!(:customer) { create(:customer_user, email: 'foo@bar.com') }
 
           it 'sets article.sender to "Customer"' do
-            Channel::EmailParser.new.process({}, raw_mail)
+            described_class.new.process({}, raw_mail)
 
             expect(Ticket.last.articles.first.sender.name).to eq('Customer')
           end
 
           it 'sets ticket.state to "new"' do
-            Channel::EmailParser.new.process({}, raw_mail)
+            described_class.new.process({}, raw_mail)
 
             expect(Ticket.last.state.name).to eq('new')
           end
@@ -149,7 +149,7 @@ RSpec.describe Channel::EmailParser, type: :model do
 
         context 'when from address is unrecognized' do
           it 'sets article.sender to "Customer"' do
-            Channel::EmailParser.new.process({}, raw_mail)
+            described_class.new.process({}, raw_mail)
 
             expect(Ticket.last.articles.first.sender.name).to eq('Customer')
           end
@@ -825,7 +825,7 @@ RSpec.describe Channel::EmailParser, type: :model do
 
       context 'when "postmaster_sender_is_agent_search_for_customer" setting is true (default)' do
         it 'sets ticket.customer to user with To: email' do
-          expect { Channel::EmailParser.new.process({}, raw_mail) }
+          expect { described_class.new.process({}, raw_mail) }
             .to change(Ticket, :count).by(1)
 
           expect(Ticket.last.customer).to eq(customer)
@@ -836,7 +836,7 @@ RSpec.describe Channel::EmailParser, type: :model do
         before { Setting.set('postmaster_sender_is_agent_search_for_customer', false) }
 
         it 'sets ticket.customer to user with To: email' do
-          expect { Channel::EmailParser.new.process({}, raw_mail) }
+          expect { described_class.new.process({}, raw_mail) }
             .to change(Ticket, :count).by(1)
 
           expect(Ticket.last.customer).to eq(agent)
@@ -1020,23 +1020,23 @@ RSpec.describe Channel::EmailParser, type: :model do
           before { ticket.update(state: Ticket::State.find_by(name: 'closed')) }
 
           it 'sets #preferences on resulting ticket to { "send-auto-responses" => false, "is-auto-reponse" => true }' do
-            article = Channel::EmailParser.new.process({}, raw_mail).second
+            article = described_class.new.process({}, raw_mail).second
             expect(article.preferences)
               .to include('send-auto-response' => false, 'is-auto-response' => true)
           end
 
           it 'returns a Mail object with an x-zammad-out-of-office header' do
-            output_mail = Channel::EmailParser.new.process({}, raw_mail).last
+            output_mail = described_class.new.process({}, raw_mail).last
             expect(output_mail).to include('x-zammad-out-of-office': true)
           end
 
           it 'finds the article referenced in the bounce message headers, then adds the bounce message to its ticket' do
-            expect { Channel::EmailParser.new.process({}, raw_mail) }
+            expect { described_class.new.process({}, raw_mail) }
               .to change { ticket.articles.count }.by(1)
           end
 
           it 'does not re-open the ticket' do
-            expect { Channel::EmailParser.new.process({}, raw_mail) }
+            expect { described_class.new.process({}, raw_mail) }
               .not_to change { ticket.reload.state.name }.from('closed')
           end
         end
@@ -1047,18 +1047,18 @@ RSpec.describe Channel::EmailParser, type: :model do
 
         context 'for original message sent by Agent' do
           it 'sets #preferences on resulting ticket to { "send-auto-responses" => false, "is-auto-reponse" => true }' do
-            article = Channel::EmailParser.new.process({}, raw_mail).second
+            article = described_class.new.process({}, raw_mail).second
             expect(article.preferences)
               .to include('send-auto-response' => false, 'is-auto-response' => true)
           end
 
           it 'finds the article referenced in the bounce message headers, then adds the bounce message to its ticket' do
-            expect { Channel::EmailParser.new.process({}, raw_mail) }
+            expect { described_class.new.process({}, raw_mail) }
               .to change { ticket.articles.count }.by(1)
           end
 
           it 'does not alter the ticket state' do
-            expect { Channel::EmailParser.new.process({}, raw_mail) }
+            expect { described_class.new.process({}, raw_mail) }
               .not_to change { ticket.reload.state.name }.from('open')
           end
         end
@@ -1067,18 +1067,18 @@ RSpec.describe Channel::EmailParser, type: :model do
           let(:article) { create(:ticket_article, sender_name: 'Customer', message_id: message_id) }
 
           it 'sets #preferences on resulting ticket to { "send-auto-responses" => false, "is-auto-reponse" => true }' do
-            article = Channel::EmailParser.new.process({}, raw_mail).second
+            article = described_class.new.process({}, raw_mail).second
             expect(article.preferences)
               .to include('send-auto-response' => false, 'is-auto-response' => true)
           end
 
           it 'finds the article referenced in the bounce message headers, then adds the bounce message to its ticket' do
-            expect { Channel::EmailParser.new.process({}, raw_mail) }
+            expect { described_class.new.process({}, raw_mail) }
               .to change { ticket.articles.count }.by(1)
           end
 
           it 'does not alter the ticket state' do
-            expect { Channel::EmailParser.new.process({}, raw_mail) }
+            expect { described_class.new.process({}, raw_mail) }
               .not_to change { ticket.reload.state.name }.from('new')
           end
         end
@@ -1088,12 +1088,12 @@ RSpec.describe Channel::EmailParser, type: :model do
         let(:mail_file) { Rails.root.join('test', 'data', 'mail', 'mail055.box') }
 
         it 'finds the article referenced in the bounce message headers, then adds the bounce message to its ticket' do
-          expect { Channel::EmailParser.new.process({}, raw_mail) }
+          expect { described_class.new.process({}, raw_mail) }
             .to change { ticket.articles.count }.by(1)
         end
 
         it 'does not alter the ticket state' do
-          expect { Channel::EmailParser.new.process({}, raw_mail) }
+          expect { described_class.new.process({}, raw_mail) }
             .not_to change { ticket.reload.state.name }.from('open')
         end
       end
@@ -1173,7 +1173,7 @@ RSpec.describe Channel::EmailParser, type: :model do
 
     shared_examples 'postmaster reply' do
       it 'composes postmaster reply' do
-        reply = Channel::EmailParser.new.send(:compose_postmaster_reply, raw_incoming_mail, locale)
+        reply = described_class.new.send(:compose_postmaster_reply, raw_incoming_mail, locale)
         expect(reply[:to]).to eq('smith@example.com')
         expect(reply[:content_type]).to eq('text/plain')
         expect(reply[:subject]).to eq(expected_subject)
@@ -1233,7 +1233,7 @@ RSpec.describe Channel::EmailParser, type: :model do
 
     shared_examples 'postmaster reply' do
       it 'composes postmaster reply' do
-        reply = Channel::EmailParser.new.send(:compose_postmaster_reply, raw_incoming_mail, locale)
+        reply = described_class.new.send(:compose_postmaster_reply, raw_incoming_mail, locale)
         expect(reply[:to]).to eq('smith@example.com')
         expect(reply[:content_type]).to eq('text/plain')
         expect(reply[:subject]).to eq(expected_subject)
diff --git a/spec/models/history_spec.rb b/spec/models/history_spec.rb
index 8550666b9..0f60f3189 100644
--- a/spec/models/history_spec.rb
+++ b/spec/models/history_spec.rb
@@ -11,7 +11,7 @@ RSpec.describe History, type: :model do
       let!(:object) { create(:'cti/log') }
 
       it 'returns an empty array' do
-        expect(History.list(object.class.name, object.id))
+        expect(described_class.list(object.class.name, object.id))
           .to be_an(Array).and be_empty
       end
     end
@@ -23,7 +23,7 @@ RSpec.describe History, type: :model do
         before { object.update(email: 'foo@example.com') }
 
         context 'or "assets" flag' do
-          let(:list) { History.list(object.class.name, object.id) }
+          let(:list) { described_class.list(object.class.name, object.id) }
 
           it 'returns an array of attribute hashes for those histories' do
             expect(list).to match_array(
@@ -58,9 +58,9 @@ RSpec.describe History, type: :model do
         end
 
         context 'but with "assets" flag' do
-          let(:list) { History.list(object.class.name, object.id, nil, true) }
+          let(:list) { described_class.list(object.class.name, object.id, nil, true) }
           let(:matching_histories) do
-            History.where(
+            described_class.where(
               o_id:              object.id,
               history_object_id: History::Object.lookup(name: object.class.name).id
             )
@@ -100,7 +100,7 @@ RSpec.describe History, type: :model do
         before { object.update(title: 'Lorem ipsum dolor') }
 
         context 'but no "assets" flag' do
-          let(:list) { History.list(object.class.name, object.id, 'Ticket::Article') }
+          let(:list) { described_class.list(object.class.name, object.id, 'Ticket::Article') }
 
           it 'returns an array of attribute hashes for those histories' do
             expect(list).to match_array(
@@ -145,12 +145,12 @@ RSpec.describe History, type: :model do
         end
 
         context 'and "assets" flag' do
-          let(:list) { History.list(object.class.name, object.id, 'Ticket::Article', true) }
+          let(:list) { described_class.list(object.class.name, object.id, 'Ticket::Article', true) }
           let(:matching_histories) do
-            History.where(
+            described_class.where(
               o_id:              object.id,
               history_object_id: History::Object.lookup(name: object.class.name).id
-            ) + History.where(
+            ) + described_class.where(
               o_id:              related_object.id,
               history_object_id: History::Object.lookup(name: related_object.class.name).id
             )
diff --git a/spec/models/import_job_spec.rb b/spec/models/import_job_spec.rb
index a99d029a4..f1a7cf8c6 100644
--- a/spec/models/import_job_spec.rb
+++ b/spec/models/import_job_spec.rb
@@ -3,39 +3,35 @@ require 'rails_helper'
 RSpec.describe ImportJob do
 
   before do
-    module Import
-      class Test < Import::Base
-        def start
-          @import_job.result = { state: 'Done' }
-        end
-      end
-    end
-
-    module Import
-      class NoRescheduleMethod
-
-        def initialize(import_job)
-          @import_job = import_job
-        end
-
-        def start
-          @import_job.result = { state: 'Done' }
-        end
-
-        def reschedule?(_delayed_job)
-          'invalid_but_checkable_result'
-        end
-      end
-    end
-  end
-
-  after do
-    Import.send(:remove_const, :Test)
-    Import.send(:remove_const, :NoRescheduleMethod)
+    stub_const test_backend_name, test_backend_class
+    stub_const test_backend_noreschedule_name, test_backend_noreschedule_class
   end
 
   let(:test_backend_name) { 'Import::Test' }
-  let(:test_backend_class) { test_backend_name.constantize }
+  let(:test_backend_class) do
+    Class.new(Import::Base) do
+      def start
+        @import_job.result = { state: 'Done' }
+      end
+    end
+  end
+
+  let(:test_backend_noreschedule_name) { 'Import::NoRescheduleMethod' }
+  let(:test_backend_noreschedule_class) do
+    Class.new do
+      def initialize(import_job)
+        @import_job = import_job
+      end
+
+      def start
+        @import_job.result = { state: 'Done' }
+      end
+
+      def reschedule?(_delayed_job)
+        'invalid_but_checkable_result'
+      end
+    end
+  end
 
   describe '#dry_run' do
 
diff --git a/spec/models/job_spec.rb b/spec/models/job_spec.rb
index 4b8f2baa8..fb7db89ab 100644
--- a/spec/models/job_spec.rb
+++ b/spec/models/job_spec.rb
@@ -37,7 +37,7 @@ RSpec.describe Job, type: :model do
       end
 
       it 'runs all executable jobs (and no others)' do
-        expect { Job.run }
+        expect { described_class.run }
           .to change { executable_jobs.map(&:reload).map(&:last_run_at).any?(&:nil?) }.to(false)
           .and not_change { nonexecutable_jobs.map(&:reload).map(&:last_run_at).all?(&:nil?) }
       end
diff --git a/spec/models/knowledge_base_spec.rb b/spec/models/knowledge_base_spec.rb
index 84c07d422..080b46dbf 100644
--- a/spec/models/knowledge_base_spec.rb
+++ b/spec/models/knowledge_base_spec.rb
@@ -6,7 +6,7 @@ RSpec.describe KnowledgeBase, type: :model do
   subject(:knowledge_base) { create(:knowledge_base) }
 
   # make sure there's no KBs from seed data
-  before { KnowledgeBase.all.each(&:full_destroy!) }
+  before { described_class.all.each(&:full_destroy!) }
 
   include_context 'factory'
 
@@ -40,25 +40,25 @@ RSpec.describe KnowledgeBase, type: :model do
         before { knowledge_base }
 
         it 'ensure 2 knowledge bases are created' do
-          expect(KnowledgeBase.count).to eq(2)
+          expect(described_class.count).to eq(2)
         end
 
         it 'filter by activity' do
-          expect(KnowledgeBase.active).to contain_exactly(knowledge_base)
+          expect(described_class.active).to contain_exactly(knowledge_base)
         end
 
         it 'skip activity check for editors when filtering by activity' do
           user = create(:admin_user)
-          expect(KnowledgeBase.check_active_unless_editor(user).count).to eq(2)
+          expect(described_class.check_active_unless_editor(user).count).to eq(2)
         end
 
         it 'check activity if user is not editor when filtering by activity' do
           user = create(:agent_user)
-          expect(KnowledgeBase.check_active_unless_editor(user)).to contain_exactly(knowledge_base)
+          expect(described_class.check_active_unless_editor(user)).to contain_exactly(knowledge_base)
         end
 
         it 'skip activity check for guests when filtering by activity' do
-          expect(KnowledgeBase.check_active_unless_editor(nil)).to contain_exactly(knowledge_base)
+          expect(described_class.check_active_unless_editor(nil)).to contain_exactly(knowledge_base)
         end
       end
     end
diff --git a/spec/models/object_lookup_spec.rb b/spec/models/object_lookup_spec.rb
index 790f184ae..d77d23c8c 100644
--- a/spec/models/object_lookup_spec.rb
+++ b/spec/models/object_lookup_spec.rb
@@ -6,7 +6,7 @@ RSpec.describe ObjectLookup, type: :model do
       subject(:object_lookup) { create(:object_lookup) }
 
       it 'returns its id' do
-        expect(ObjectLookup.by_name(object_lookup.name))
+        expect(described_class.by_name(object_lookup.name))
           .to eq(object_lookup.id)
       end
     end
@@ -15,24 +15,24 @@ RSpec.describe ObjectLookup, type: :model do
       let(:name) { 'FooBar' }
 
       it 'creates a new one with that name' do
-        expect { ObjectLookup.by_name(name) }
-          .to change(ObjectLookup, :count).by(1)
+        expect { described_class.by_name(name) }
+          .to change(described_class, :count).by(1)
 
-        expect(ObjectLookup.last.name).to eq(name)
+        expect(described_class.last.name).to eq(name)
       end
 
       it 'returns its id' do
-        expect(ObjectLookup.by_name(name))
-          .to eq(ObjectLookup.last.id)
+        expect(described_class.by_name(name))
+          .to eq(described_class.last.id)
       end
 
       context 'for names not in strict CamelCase' do
         let(:name) { 'Foo_Bar' }
 
         it 'does not modify the format' do
-          ObjectLookup.by_name(name)
+          described_class.by_name(name)
 
-          expect(ObjectLookup.last.name).to eq(name)
+          expect(described_class.last.name).to eq(name)
         end
       end
     end
@@ -43,7 +43,7 @@ RSpec.describe ObjectLookup, type: :model do
       subject(:object_lookup) { create(:object_lookup) }
 
       it 'returns its name' do
-        expect(ObjectLookup.by_id(object_lookup.id))
+        expect(described_class.by_id(object_lookup.id))
           .to eq(object_lookup.name)
       end
     end
diff --git a/spec/models/object_manager/attribute_spec.rb b/spec/models/object_manager/attribute_spec.rb
index a6c41b29d..523b6da4c 100644
--- a/spec/models/object_manager/attribute_spec.rb
+++ b/spec/models/object_manager/attribute_spec.rb
@@ -53,14 +53,14 @@ RSpec.describe ObjectManager::Attribute, type: :model do
   describe 'check name' do
     it 'rejects ActiveRecord reserved word "attribute"' do
       expect do
-        ObjectManager::Attribute.add attributes_for :object_manager_attribute_text, name: 'attribute'
+        described_class.add attributes_for :object_manager_attribute_text, name: 'attribute'
       end.to raise_error 'attribute is a reserved word, please choose a different one'
     end
 
     %w[destroy true false integer select drop create alter index table varchar blob date datetime timestamp url icon initials avatar permission validate subscribe unsubscribe translate search _type _doc _id id].each do |reserved_word|
       it "rejects Zammad reserved word '#{reserved_word}'" do
         expect do
-          ObjectManager::Attribute.add attributes_for :object_manager_attribute_text, name: reserved_word
+          described_class.add attributes_for :object_manager_attribute_text, name: reserved_word
         end.to raise_error "#{reserved_word} is a reserved word, please choose a different one"
       end
     end
@@ -68,41 +68,41 @@ RSpec.describe ObjectManager::Attribute, type: :model do
     %w[someting_id something_ids].each do |reserved_word|
       it "rejects word '#{reserved_word}' which is used for database references" do
         expect do
-          ObjectManager::Attribute.add attributes_for :object_manager_attribute_text, name: reserved_word
+          described_class.add attributes_for :object_manager_attribute_text, name: reserved_word
         end.to raise_error "Name can't get used, *_id and *_ids are not allowed"
       end
     end
 
     it 'rejects duplicate attribute name of conflicting types' do
       attribute = attributes_for :object_manager_attribute_text
-      ObjectManager::Attribute.add attribute
+      described_class.add attribute
       attribute[:data_type] = 'boolean'
       expect do
-        ObjectManager::Attribute.add attribute
+        described_class.add attribute
       end.to raise_error ActiveRecord::RecordInvalid
     end
 
     it 'accepts duplicate attribute name on the same types (editing an existing attribute)' do
       attribute = attributes_for :object_manager_attribute_text
-      ObjectManager::Attribute.add attribute
+      described_class.add attribute
       expect do
-        ObjectManager::Attribute.add attribute
+        described_class.add attribute
       end.not_to raise_error
     end
 
     it 'accepts duplicate attribute name on compatible types (editing the type of an existing attribute)' do
       attribute = attributes_for :object_manager_attribute_text
-      ObjectManager::Attribute.add attribute
+      described_class.add attribute
       attribute[:data_type] = 'select'
       attribute[:data_option_new] = { default: '', options: { 'a' => 'a' } }
       expect do
-        ObjectManager::Attribute.add attribute
+        described_class.add attribute
       end.not_to raise_error
     end
 
     it 'accepts valid attribute names' do
       expect do
-        ObjectManager::Attribute.add attributes_for :object_manager_attribute_text
+        described_class.add attributes_for :object_manager_attribute_text
       end.not_to raise_error
     end
   end
diff --git a/spec/models/permission_spec.rb b/spec/models/permission_spec.rb
index af15f6bc9..68b79c0c3 100644
--- a/spec/models/permission_spec.rb
+++ b/spec/models/permission_spec.rb
@@ -4,13 +4,13 @@ RSpec.describe Permission, type: :model do
   describe '.with_parents' do
     context 'when given a simple string (no dots)' do
       it 'returns an array containing only that string' do
-        expect(Permission.with_parents('foo')).to eq(['foo'])
+        expect(described_class.with_parents('foo')).to eq(['foo'])
       end
     end
 
     context 'when given a String permission name (dot-delimited identifier)' do
       it 'returns an array of String ancestors (desc. from root)' do
-        expect(Permission.with_parents('foo.bar.baz'))
+        expect(described_class.with_parents('foo.bar.baz'))
           .to eq(%w[foo foo.bar foo.bar.baz])
       end
     end
diff --git a/spec/models/recent_view_spec.rb b/spec/models/recent_view_spec.rb
index d287d49e5..322bc0ce3 100644
--- a/spec/models/recent_view_spec.rb
+++ b/spec/models/recent_view_spec.rb
@@ -138,7 +138,7 @@ RSpec.describe RecentView, type: :model do
     it 'wraps RecentView.create' do
       expect do
         described_class.log(viewed_object.class.name, viewed_object.id, admin)
-      end.to change(RecentView, :count).by(1)
+      end.to change(described_class, :count).by(1)
     end
 
     describe 'access privileges' do
@@ -152,7 +152,7 @@ RSpec.describe RecentView, type: :model do
 
         expect do
           described_class.log(viewed_object.class.name, viewed_object.id, agent)
-        end.not_to change(RecentView, :count)
+        end.not_to change(described_class, :count)
       end
     end
 
@@ -160,19 +160,19 @@ RSpec.describe RecentView, type: :model do
       it 'does not create RecentView for non-existent record' do
         expect do
           described_class.log('User', 99_999_999, admin)
-        end.not_to change(RecentView, :count)
+        end.not_to change(described_class, :count)
       end
 
       it 'does not create RecentView for instance of non-ObjectLookup class' do
         expect do
           described_class.log('Overview', 1, admin)
-        end.not_to change(RecentView, :count)
+        end.not_to change(described_class, :count)
       end
 
       it 'does not create RecentView for instance of non-existent class' do
         expect do
           described_class.log('NonExistentClass', 1, admin)
-        end.not_to change(RecentView, :count)
+        end.not_to change(described_class, :count)
       end
     end
   end
diff --git a/spec/models/scheduler_spec.rb b/spec/models/scheduler_spec.rb
index 0f11afc74..e0b9a03ef 100644
--- a/spec/models/scheduler_spec.rb
+++ b/spec/models/scheduler_spec.rb
@@ -2,29 +2,27 @@ require 'rails_helper'
 
 RSpec.describe Scheduler do
 
-  before do
-    module SpecSpace
-      class DelayedJobBackend
+  let(:test_backend_name) { 'SpecSpace::DelayedJobBackend' }
+  let(:test_backend_class) do
+    Class.new do
+      def self.start
+        # noop
+      end
 
-        def self.start
-          # noop
-        end
+      # rubocop:disable Style/TrivialAccessors
+      def self.reschedule=(reschedule)
+        @reschedule = reschedule
+      end
+      # rubocop:enable Style/TrivialAccessors
 
-        # rubocop:disable Style/TrivialAccessors
-        def self.reschedule=(reschedule)
-          @reschedule = reschedule
-        end
-        # rubocop:enable Style/TrivialAccessors
-
-        def self.reschedule?(_delayed_job)
-          @reschedule || false
-        end
+      def self.reschedule?(_delayed_job)
+        @reschedule || false
       end
     end
   end
 
-  after do
-    SpecSpace.send(:remove_const, :DelayedJobBackend)
+  before do
+    stub_const test_backend_name, test_backend_class
   end
 
   describe '.failed_jobs' do
diff --git a/spec/models/setting_spec.rb b/spec/models/setting_spec.rb
index e29130847..34eff28c8 100644
--- a/spec/models/setting_spec.rb
+++ b/spec/models/setting_spec.rb
@@ -7,7 +7,7 @@ RSpec.describe Setting, type: :model do
     context 'when given a valid Setting#name' do
       it 'returns #state_current[:value]' do
         expect { setting.update(state_current: { value: 'foo' }) }
-          .to change { Setting.get(setting.name) }.to('foo')
+          .to change { described_class.get(setting.name) }.to('foo')
       end
     end
   end
@@ -15,7 +15,7 @@ RSpec.describe Setting, type: :model do
   describe '.set' do
     context 'when given a valid Setting#name' do
       it 'sets #state_current = { value: <arg> }' do
-        expect { Setting.set(setting.name, 'foo') }
+        expect { described_class.set(setting.name, 'foo') }
           .to change { setting.reload.state_current }.to({ 'value' => 'foo' })
       end
     end
@@ -26,7 +26,7 @@ RSpec.describe Setting, type: :model do
       before { Cache.write('foo', 'bar') }
 
       it 'resets the cache key' do
-        expect { Setting.set(setting.name, 'baz') }
+        expect { described_class.set(setting.name, 'baz') }
           .to change { Cache.get('foo') }.to(nil)
       end
     end
@@ -36,9 +36,9 @@ RSpec.describe Setting, type: :model do
     context 'when given a valid Setting#name' do
       it 'sets #state_current = { value: <orig> } (via #state_initial[:value])' do
         setting.update(state_initial: { value: 'foo' })
-        Setting.set(setting.name, 'bar')
+        described_class.set(setting.name, 'bar')
 
-        expect { Setting.reset(setting.name) }
+        expect { described_class.reset(setting.name) }
           .to change { setting.reload.state_current }.to({ value: 'foo' })
       end
     end
diff --git a/spec/models/tag_spec.rb b/spec/models/tag_spec.rb
index c960c9142..ae089aef6 100644
--- a/spec/models/tag_spec.rb
+++ b/spec/models/tag_spec.rb
@@ -12,9 +12,9 @@ RSpec.describe Tag, type: :model do
     context 'when a Tag::Object does not exist for the given class' do
       it 'creates it and assigns it to a new Tag' do
         expect { described_class.tag_add(object: 'Foo', item: 'bar', o_id: 1, created_by_id: 1) }
-          .to change(Tag, :count).by(1)
+          .to change(described_class, :count).by(1)
           .and change { Tag::Object.exists?(name: 'Foo') }.to(true)
-          .and change { Tag.last&.tag_object&.name }.to('Foo')
+          .and change { described_class.last&.tag_object&.name }.to('Foo')
       end
     end
 
@@ -23,33 +23,33 @@ RSpec.describe Tag, type: :model do
 
       it 'assigns it to a new Tag' do
         expect { described_class.tag_add(object: 'Ticket', item: 'foo', o_id: 1, created_by_id: 1) }
-          .to change(Tag, :count).by(1)
+          .to change(described_class, :count).by(1)
           .and not_change(Tag::Object, :count)
-          .and change { Tag.last&.tag_object&.name }.to('Ticket')
+          .and change { described_class.last&.tag_object&.name }.to('Ticket')
       end
     end
 
     context 'when a Tag::Item does not exist with the given name' do
       it 'creates it and assigns it to a new Tag' do
         expect { described_class.tag_add(object: 'Ticket', item: 'foo', o_id: 1, created_by_id: 1) }
-          .to change(Tag, :count).by(1)
+          .to change(described_class, :count).by(1)
           .and change { Tag::Item.exists?(name: 'foo') }.to(true)
-          .and change { Tag.last&.tag_item&.name }.to('foo')
+          .and change { described_class.last&.tag_item&.name }.to('foo')
       end
 
       it 'strips trailing/leading whitespace' do
         expect { described_class.tag_add(object: 'Ticket', item: '  foo ', o_id: 1, created_by_id: 1) }
-          .to change(Tag, :count).by(1)
+          .to change(described_class, :count).by(1)
           .and change { Tag::Item.exists?(name: 'foo') }.to(true)
-          .and change { Tag.last&.tag_item&.name }.to('foo')
+          .and change { described_class.last&.tag_item&.name }.to('foo')
       end
 
       context 'and the name contains 8-bit Unicode characters' do
         it 'creates it and assigns it to a new Tag' do
           expect { described_class.tag_add(object: 'Ticket', item: 'fooöäüß', o_id: 1, created_by_id: 1) }
-            .to change(Tag, :count).by(1)
+            .to change(described_class, :count).by(1)
             .and change { Tag::Item.exists?(name: 'fooöäüß') }.to(true)
-            .and change { Tag.last&.tag_item&.name }.to('fooöäüß')
+            .and change { described_class.last&.tag_item&.name }.to('fooöäüß')
         end
       end
 
@@ -58,9 +58,9 @@ RSpec.describe Tag, type: :model do
 
         it 'creates it and assigns it to a new Tag' do
           expect { described_class.tag_add(object: 'Ticket', item: 'FOO', o_id: 1, created_by_id: 1) }
-            .to change(Tag, :count).by(1)
+            .to change(described_class, :count).by(1)
             .and change { Tag::Item.pluck(:name).include?('FOO') }.to(true) # .exists?(name: 'FOO') fails on MySQL
-            .and change { Tag.last&.tag_item&.name }.to('FOO')
+            .and change { described_class.last&.tag_item&.name }.to('FOO')
         end
       end
     end
@@ -70,16 +70,16 @@ RSpec.describe Tag, type: :model do
 
       it 'assigns it to a new Tag' do
         expect { described_class.tag_add(object: 'Ticket', item: 'foo', o_id: 1, created_by_id: 1) }
-          .to change(Tag, :count).by(1)
+          .to change(described_class, :count).by(1)
           .and not_change(Tag::Item, :count)
-          .and change { Tag.last&.tag_item&.name }.to('foo')
+          .and change { described_class.last&.tag_item&.name }.to('foo')
       end
 
       it 'strips leading/trailing whitespace' do
         expect { described_class.tag_add(object: 'Ticket', item: '  foo ', o_id: 1, created_by_id: 1) }
-          .to change(Tag, :count).by(1)
+          .to change(described_class, :count).by(1)
           .and not_change(Tag::Item, :count)
-          .and change { Tag.last&.tag_item&.name }.to('foo')
+          .and change { described_class.last&.tag_item&.name }.to('foo')
       end
     end
 
@@ -89,7 +89,7 @@ RSpec.describe Tag, type: :model do
 
       it 'does not create any records' do
         expect { described_class.tag_add(object: 'Ticket', item: 'foo', o_id: Ticket.first.id, created_by_id: 1) }
-          .to not_change(Tag, :count)
+          .to not_change(described_class, :count)
           .and not_change(Tag::Item, :count)
       end
     end
@@ -107,14 +107,14 @@ RSpec.describe Tag, type: :model do
 
       it 'destroys the Tag' do
         expect { described_class.tag_remove(object: 'Ticket', o_id: Ticket.first.id, item: 'foo') }
-          .to change(Tag, :count).by(-1)
+          .to change(described_class, :count).by(-1)
       end
     end
 
     context 'when no matching Tag exists' do
       it 'makes no changes' do
         expect { described_class.tag_remove(object: 'Ticket', o_id: Ticket.first.id, item: 'foo') }
-          .not_to change(Tag, :count)
+          .not_to change(described_class, :count)
       end
     end
   end
diff --git a/spec/models/ticket/priority_spec.rb b/spec/models/ticket/priority_spec.rb
index c775a4f18..a26b89dfb 100644
--- a/spec/models/ticket/priority_spec.rb
+++ b/spec/models/ticket/priority_spec.rb
@@ -9,7 +9,7 @@ RSpec.describe Ticket::Priority, type: :model do
   describe 'Default state' do
     describe 'of whole table:' do
       it 'has exactly one default record' do
-        expect(Ticket::Priority.where(default_create: true)).to be_one
+        expect(described_class.where(default_create: true)).to be_one
       end
     end
   end
@@ -18,21 +18,21 @@ RSpec.describe Ticket::Priority, type: :model do
     describe '#default_create' do
       it 'cannot be true for more than one record at a time' do
         expect { create(:'ticket/priority', default_create: true) }
-          .to change { Ticket::Priority.find_by(default_create: true).id }
-          .and change { Ticket::Priority.where(default_create: true).count }.by(0)
+          .to change { described_class.find_by(default_create: true).id }
+          .and change { described_class.where(default_create: true).count }.by(0)
       end
 
       it 'cannot be false for all records' do
         create(:'ticket/priority', default_create: true)
 
-        expect { Ticket::Priority.find_by(default_create: true).destroy }
-          .to change { Ticket::Priority.find_by(default_create: true).id }
-          .and change { Ticket::Priority.where(default_create: true).count }.by(0)
+        expect { described_class.find_by(default_create: true).destroy }
+          .to change { described_class.find_by(default_create: true).id }
+          .and change { described_class.where(default_create: true).count }.by(0)
       end
 
       it 'is not automatically set to the last-created record' do
         expect { create(:'ticket/priority') }
-          .not_to change { Ticket::Priority.find_by(default_create: true).id }
+          .not_to change { described_class.find_by(default_create: true).id }
       end
     end
   end
diff --git a/spec/models/ticket/state_spec.rb b/spec/models/ticket/state_spec.rb
index e07f08639..48369554b 100644
--- a/spec/models/ticket/state_spec.rb
+++ b/spec/models/ticket/state_spec.rb
@@ -9,22 +9,22 @@ RSpec.describe Ticket::State, type: :model do
   describe 'Default state' do
     describe 'of whole table:' do
       it 'has seven records' do
-        expect(Ticket::State.pluck(:name))
+        expect(described_class.pluck(:name))
           .to match_array(%w[closed merged new open pending\ close pending\ reminder removed])
       end
     end
 
     describe 'of "new" state:' do
       it 'is the sole #default_create state' do
-        expect(Ticket::State.where(default_create: true))
-          .to match_array([Ticket::State.find_by(name: 'new')])
+        expect(described_class.where(default_create: true))
+          .to match_array([described_class.find_by(name: 'new')])
       end
     end
 
     describe 'of "open" state:' do
       it 'is the sole #default_follow_up state' do
-        expect(Ticket::State.where(default_follow_up: true))
-          .to match_array([Ticket::State.find_by(name: 'open')])
+        expect(described_class.where(default_follow_up: true))
+          .to match_array([described_class.find_by(name: 'open')])
       end
     end
   end
@@ -34,7 +34,7 @@ RSpec.describe Ticket::State, type: :model do
       it 'looks up states by category' do
         expect(described_class.by_category(:open))
           .to be_an(ActiveRecord::Relation)
-          .and include(instance_of(Ticket::State))
+          .and include(instance_of(described_class))
       end
 
       context 'with invalid category name' do
@@ -48,7 +48,7 @@ RSpec.describe Ticket::State, type: :model do
 
   describe 'Attributes:' do
     describe '#default_create' do
-      let!(:original_default) { Ticket::State.find_by(default_create: true) }
+      let!(:original_default) { described_class.find_by(default_create: true) }
 
       context 'for newly created record' do
         subject!(:state) { build(:ticket_state, default_create: default_create) }
@@ -59,7 +59,7 @@ RSpec.describe Ticket::State, type: :model do
           it 'unsets previous default' do
             expect { state.save }
               .to change { original_default.reload.default_create }.to(false)
-              .and not_change { Ticket::State.where(default_create: true).count }
+              .and not_change { described_class.where(default_create: true).count }
           end
         end
 
@@ -68,8 +68,8 @@ RSpec.describe Ticket::State, type: :model do
 
           it 'does not alter existing default' do
             expect { state.save }
-              .to not_change { Ticket::State.find_by(default_create: true) }
-              .and not_change { Ticket::State.where(default_create: true).count }
+              .to not_change { described_class.find_by(default_create: true) }
+              .and not_change { described_class.where(default_create: true).count }
           end
         end
       end
@@ -83,16 +83,16 @@ RSpec.describe Ticket::State, type: :model do
           context 'and updated to false' do
             it 'assigns Ticket::State.first as default' do
               expect { state.update(default_create: false) }
-                .to change { Ticket::State.first.default_create }.to(true)
-                .and not_change { Ticket::State.where(default_create: true).count }
+                .to change { described_class.first.default_create }.to(true)
+                .and not_change { described_class.where(default_create: true).count }
             end
           end
 
           context 'and destroyed' do
             it 'assigns Ticket::State.first as default' do
               expect { state.destroy }
-                .to change { Ticket::State.first.default_create }.to(true)
-                .and not_change { Ticket::State.where(default_create: true).count }
+                .to change { described_class.first.default_create }.to(true)
+                .and not_change { described_class.where(default_create: true).count }
             end
           end
         end
@@ -104,15 +104,15 @@ RSpec.describe Ticket::State, type: :model do
             it 'unsets previous default' do
               expect { state.update(default_create: true) }
                 .to change { original_default.reload.default_create }.to(false)
-                .and not_change { Ticket::State.where(default_create: true).count }
+                .and not_change { described_class.where(default_create: true).count }
             end
           end
 
           context 'and destroyed' do
             it 'does not alter existing default' do
               expect { state.destroy }
-                .to not_change { Ticket::State.find_by(default_create: true) }
-                .and not_change { Ticket::State.where(default_create: true).count }
+                .to not_change { described_class.find_by(default_create: true) }
+                .and not_change { described_class.where(default_create: true).count }
             end
           end
         end
@@ -120,7 +120,7 @@ RSpec.describe Ticket::State, type: :model do
     end
 
     describe '#default_follow_up' do
-      let!(:original_default) { Ticket::State.find_by(default_follow_up: true) }
+      let!(:original_default) { described_class.find_by(default_follow_up: true) }
 
       context 'for newly created record' do
         subject!(:state) { build(:ticket_state, default_follow_up: default_follow_up) }
@@ -131,7 +131,7 @@ RSpec.describe Ticket::State, type: :model do
           it 'unsets previous default' do
             expect { state.save }
               .to change { original_default.reload.default_follow_up }.to(false)
-              .and not_change { Ticket::State.where(default_follow_up: true).count }
+              .and not_change { described_class.where(default_follow_up: true).count }
           end
         end
 
@@ -140,8 +140,8 @@ RSpec.describe Ticket::State, type: :model do
 
           it 'does not alter existing default' do
             expect { state.save }
-              .to not_change { Ticket::State.find_by(default_follow_up: true) }
-              .and not_change { Ticket::State.where(default_follow_up: true).count }
+              .to not_change { described_class.find_by(default_follow_up: true) }
+              .and not_change { described_class.where(default_follow_up: true).count }
           end
         end
       end
@@ -155,16 +155,16 @@ RSpec.describe Ticket::State, type: :model do
           context 'and updated to false' do
             it 'assigns Ticket::State.first as default' do
               expect { state.update(default_follow_up: false) }
-                .to change { Ticket::State.first.default_follow_up }.to(true)
-                .and not_change { Ticket::State.where(default_follow_up: true).count }
+                .to change { described_class.first.default_follow_up }.to(true)
+                .and not_change { described_class.where(default_follow_up: true).count }
             end
           end
 
           context 'and destroyed' do
             it 'assigns Ticket::State.first as default' do
               expect { state.destroy }
-                .to change { Ticket::State.first.default_follow_up }.to(true)
-                .and not_change { Ticket::State.where(default_follow_up: true).count }
+                .to change { described_class.first.default_follow_up }.to(true)
+                .and not_change { described_class.where(default_follow_up: true).count }
             end
           end
         end
@@ -176,15 +176,15 @@ RSpec.describe Ticket::State, type: :model do
             it 'unsets previous default' do
               expect { state.update(default_follow_up: true) }
                 .to change { original_default.reload.default_follow_up }.to(false)
-                .and not_change { Ticket::State.where(default_follow_up: true).count }
+                .and not_change { described_class.where(default_follow_up: true).count }
             end
           end
 
           context 'and destroyed' do
             it 'does not alter existing default' do
               expect { state.destroy }
-                .to not_change { Ticket::State.find_by(default_follow_up: true) }
-                .and not_change { Ticket::State.where(default_follow_up: true).count }
+                .to not_change { described_class.find_by(default_follow_up: true) }
+                .and not_change { described_class.where(default_follow_up: true).count }
             end
           end
         end
diff --git a/spec/models/ticket/time_accounting_spec.rb b/spec/models/ticket/time_accounting_spec.rb
index 6ef6f4954..ea339387d 100644
--- a/spec/models/ticket/time_accounting_spec.rb
+++ b/spec/models/ticket/time_accounting_spec.rb
@@ -11,7 +11,7 @@ RSpec.describe Ticket::TimeAccounting, type: :model do
         it 'destroys self' do
           expect { time_accounting.ticket_article.destroy }
             .to change(time_accounting, :persisted?).to(false)
-            .and change { Ticket::TimeAccounting.count }.by(-1)
+            .and change(described_class, :count).by(-1)
         end
 
         it 'does not destroy other TimeAccountings for same ticket' do
@@ -19,7 +19,7 @@ RSpec.describe Ticket::TimeAccounting, type: :model do
           create(:'ticket/time_accounting', :for_article, ticket: time_accounting.ticket)
 
           expect { time_accounting.ticket_article.destroy }
-            .to change { Ticket::TimeAccounting.count }.by(-1)
+            .to change(described_class, :count).by(-1)
         end
       end
     end
diff --git a/spec/models/ticket_spec.rb b/spec/models/ticket_spec.rb
index c4bf17126..0944d79d1 100644
--- a/spec/models/ticket_spec.rb
+++ b/spec/models/ticket_spec.rb
@@ -43,7 +43,7 @@ RSpec.describe Ticket, type: :model do
         end
 
         it 'returns a list of unique tickets (i.e., no duplicates)' do
-          expect(Ticket.selectors(condition, limit: 100, access: 'full'))
+          expect(described_class.selectors(condition, limit: 100, access: 'full'))
             .to match_array([2, tickets.to_a])
         end
       end
diff --git a/spec/models/token_spec.rb b/spec/models/token_spec.rb
index c12d0590c..cba373674 100644
--- a/spec/models/token_spec.rb
+++ b/spec/models/token_spec.rb
@@ -6,19 +6,19 @@ RSpec.describe Token, type: :model do
   describe '.check' do
     context 'with name and action matching existing token' do
       it 'returns the token’s user' do
-        expect(Token.check(action: token.action, name: token.name)).to eq(token.user)
+        expect(described_class.check(action: token.action, name: token.name)).to eq(token.user)
       end
     end
 
     context 'with invalid name' do
       it 'returns nil' do
-        expect(Token.check(action: token.action, name: '1NV4L1D')).to be(nil)
+        expect(described_class.check(action: token.action, name: '1NV4L1D')).to be(nil)
       end
     end
 
     context 'with invalid action' do
       it 'returns nil' do
-        expect(Token.check(action: 'PasswordReset_NotExisting', name: token.name)).to be(nil)
+        expect(described_class.check(action: 'PasswordReset_NotExisting', name: token.name)).to be(nil)
       end
     end
 
@@ -30,14 +30,14 @@ RSpec.describe Token, type: :model do
           let(:created_at) { 1.month.ago }
 
           it 'returns the token’s user' do
-            expect(Token.check(action: token.action, name: token.name)).to eq(token.user)
+            expect(described_class.check(action: token.action, name: token.name)).to eq(token.user)
           end
 
           it 'does not delete the token' do
             token  # create token
 
-            expect { Token.check(action: token.action, name: token.name) }
-              .not_to change(Token, :count)
+            expect { described_class.check(action: token.action, name: token.name) }
+              .not_to change(described_class, :count)
           end
         end
       end
@@ -49,14 +49,14 @@ RSpec.describe Token, type: :model do
           let(:created_at) { 1.day.ago + 5 }
 
           it 'returns the token’s user' do
-            expect(Token.check(action: token.action, name: token.name)).to eq(token.user)
+            expect(described_class.check(action: token.action, name: token.name)).to eq(token.user)
           end
 
           it 'does not delete the token' do
             token  # create token
 
-            expect { Token.check(action: token.action, name: token.name) }
-              .not_to change(Token, :count)
+            expect { described_class.check(action: token.action, name: token.name) }
+              .not_to change(described_class, :count)
           end
         end
 
@@ -64,14 +64,14 @@ RSpec.describe Token, type: :model do
           let(:created_at) { 1.day.ago }
 
           it 'returns nil' do
-            expect(Token.check(action: token.action, name: token.name)).to be(nil)
+            expect(described_class.check(action: token.action, name: token.name)).to be(nil)
           end
 
           it 'deletes the token' do
             token  # create token
 
-            expect { Token.check(action: token.action, name: token.name) }
-              .to change(Token, :count).by(-1)
+            expect { described_class.check(action: token.action, name: token.name) }
+              .to change(described_class, :count).by(-1)
           end
         end
       end
@@ -85,43 +85,43 @@ RSpec.describe Token, type: :model do
 
       context 'with a permission shared by both token.user and token.preferences' do
         it 'returns token.user' do
-          expect(Token.check(action: token.action, name: token.name, permission: 'ticket.agent')).to eq(agent)
+          expect(described_class.check(action: token.action, name: token.name, permission: 'ticket.agent')).to eq(agent)
         end
       end
 
       context 'with the child of a permission shared by both token.user and token.preferences' do
         it 'returns token.user' do
-          expect(Token.check(action: token.action, name: token.name, permission: 'ticket.agent.foo')).to eq(agent)
+          expect(described_class.check(action: token.action, name: token.name, permission: 'ticket.agent.foo')).to eq(agent)
         end
       end
 
       context 'with the parent of a permission shared by both token.user and token.preferences' do
         it 'returns nil' do
-          expect(Token.check(action: token.action, name: token.name, permission: 'ticket')).to be(nil)
+          expect(described_class.check(action: token.action, name: token.name, permission: 'ticket')).to be(nil)
         end
       end
 
       context 'with a permission in token.preferences, but not on token.user' do
         it 'returns nil' do
-          expect(Token.check(action: token.action, name: token.name, permission: 'admin')).to be(nil)
+          expect(described_class.check(action: token.action, name: token.name, permission: 'admin')).to be(nil)
         end
       end
 
       context 'with a permission not in token.preferences, but on token.user' do
         it 'returns nil' do
-          expect(Token.check(action: token.action, name: token.name, permission: 'cti.agent')).to be(nil)
+          expect(described_class.check(action: token.action, name: token.name, permission: 'cti.agent')).to be(nil)
         end
       end
 
       context 'with non-existent permission' do
         it 'returns nil' do
-          expect(Token.check(action: token.action, name: token.name, permission: 'foo')).to be(nil)
+          expect(described_class.check(action: token.action, name: token.name, permission: 'foo')).to be(nil)
         end
       end
 
       context 'with multiple permissions, where at least one is shared by both token.user and token.preferences' do
         it 'returns token.user' do
-          expect(Token.check(action: token.action, name: token.name, permission: %w[foo ticket.agent])).to eq(agent)
+          expect(described_class.check(action: token.action, name: token.name, permission: %w[foo ticket.agent])).to eq(agent)
         end
       end
     end
@@ -130,7 +130,7 @@ RSpec.describe Token, type: :model do
   describe 'Attributes:' do
     describe '#persistent' do
       context 'when not set on creation' do
-        subject(:token) { Token.create(action: 'foo', user_id: User.first.id) }
+        subject(:token) { described_class.create(action: 'foo', user_id: User.first.id) }
 
         it 'defaults to nil' do
           expect(token.persistent).to be(nil)
diff --git a/spec/models/trigger_spec.rb b/spec/models/trigger_spec.rb
index 75d2146c4..d47a2edb4 100644
--- a/spec/models/trigger_spec.rb
+++ b/spec/models/trigger_spec.rb
@@ -8,7 +8,7 @@ RSpec.describe Trigger, type: :model do
 
   describe 'Send-email triggers' do
     before do
-      Trigger.destroy_all  # Default DB state includes three sample triggers
+      described_class.destroy_all  # Default DB state includes three sample triggers
       trigger              # create subject trigger
     end
 
diff --git a/spec/models/type_lookup_spec.rb b/spec/models/type_lookup_spec.rb
index 0edb45c07..bcc2b71f9 100644
--- a/spec/models/type_lookup_spec.rb
+++ b/spec/models/type_lookup_spec.rb
@@ -6,7 +6,7 @@ RSpec.describe TypeLookup, type: :model do
       subject(:type_lookup) { create(:type_lookup) }
 
       it 'returns its id' do
-        expect(TypeLookup.by_name(type_lookup.name))
+        expect(described_class.by_name(type_lookup.name))
           .to eq(type_lookup.id)
       end
     end
@@ -15,24 +15,24 @@ RSpec.describe TypeLookup, type: :model do
       let(:name) { 'FooBar' }
 
       it 'creates a new one with that name' do
-        expect { TypeLookup.by_name(name) }
-          .to change(TypeLookup, :count).by(1)
+        expect { described_class.by_name(name) }
+          .to change(described_class, :count).by(1)
 
-        expect(TypeLookup.last.name).to eq(name)
+        expect(described_class.last.name).to eq(name)
       end
 
       it 'returns its id' do
-        expect(TypeLookup.by_name(name))
-          .to eq(TypeLookup.last.id)
+        expect(described_class.by_name(name))
+          .to eq(described_class.last.id)
       end
 
       context 'for names not in strict CamelCase' do
         let(:name) { 'Foo_Bar' }
 
         it 'does not modify the format' do
-          TypeLookup.by_name(name)
+          described_class.by_name(name)
 
-          expect(TypeLookup.last.name).to eq(name)
+          expect(described_class.last.name).to eq(name)
         end
       end
     end
@@ -43,7 +43,7 @@ RSpec.describe TypeLookup, type: :model do
       subject(:type_lookup) { create(:type_lookup) }
 
       it 'returns its name' do
-        expect(TypeLookup.by_id(type_lookup.id))
+        expect(described_class.by_id(type_lookup.id))
           .to eq(type_lookup.name)
       end
     end
diff --git a/spec/models/user_device_spec.rb b/spec/models/user_device_spec.rb
index ffb12b6c6..2f27e3223 100644
--- a/spec/models/user_device_spec.rb
+++ b/spec/models/user_device_spec.rb
@@ -2,7 +2,7 @@ require 'rails_helper'
 
 RSpec.describe UserDevice, type: :model do
   describe '.add' do
-    let(:existing_record) { UserDevice.add(user_agent, ip, agent.id, fingerprint, type) }
+    let(:existing_record) { described_class.add(user_agent, ip, agent.id, fingerprint, type) }
     let(:ip) { '91.115.248.231' }
     let(:agent) { create(:agent_user) }
 
@@ -15,7 +15,7 @@ RSpec.describe UserDevice, type: :model do
 
       context 'when called with same parameters as existing record' do
         it 'returns the original record' do
-          expect(UserDevice.add(user_agent, ip, agent.id, fingerprint, type))
+          expect(described_class.add(user_agent, ip, agent.id, fingerprint, type))
             .to eq(existing_record)
         end
       end
@@ -24,8 +24,8 @@ RSpec.describe UserDevice, type: :model do
         let(:other_ip) { '176.198.137.254' }
 
         it 'returns a new record' do
-          expect(UserDevice.add(user_agent, other_ip, agent.id, fingerprint, type))
-            .to be_a(UserDevice)
+          expect(described_class.add(user_agent, other_ip, agent.id, fingerprint, type))
+            .to be_a(described_class)
             .and not_eq(existing_record)
         end
       end
@@ -34,8 +34,8 @@ RSpec.describe UserDevice, type: :model do
         let(:other_ip) { 'foo' }
 
         it 'returns a new record' do
-          expect(UserDevice.add(user_agent, other_ip, agent.id, fingerprint, type))
-            .to be_a(UserDevice)
+          expect(described_class.add(user_agent, other_ip, agent.id, fingerprint, type))
+            .to be_a(described_class)
             .and not_eq(existing_record)
         end
       end
@@ -44,8 +44,8 @@ RSpec.describe UserDevice, type: :model do
         let(:other_fingerprint) { 'fingerprintABCD' }
 
         it 'returns a new record' do
-          expect(UserDevice.add(user_agent, ip, agent.id, other_fingerprint, type))
-            .to be_a(UserDevice)
+          expect(described_class.add(user_agent, ip, agent.id, other_fingerprint, type))
+            .to be_a(described_class)
             .and not_eq(existing_record)
         end
       end
@@ -112,7 +112,7 @@ RSpec.describe UserDevice, type: :model do
 
       context 'when called with same parameters as existing record' do
         it 'returns the original record' do
-          expect(UserDevice.add(user_agent, ip, agent.id, fingerprint, type))
+          expect(described_class.add(user_agent, ip, agent.id, fingerprint, type))
             .to eq(existing_record)
         end
       end
@@ -121,8 +121,8 @@ RSpec.describe UserDevice, type: :model do
         let(:other_ip) { '176.198.137.254' }
 
         it 'returns a new record' do
-          expect(UserDevice.add(user_agent, other_ip, agent.id, fingerprint, type))
-            .to be_a(UserDevice)
+          expect(described_class.add(user_agent, other_ip, agent.id, fingerprint, type))
+            .to be_a(described_class)
             .and not_eq(existing_record)
         end
       end
@@ -131,7 +131,7 @@ RSpec.describe UserDevice, type: :model do
         let(:other_type) { 'token_auth' }
 
         it 'returns the original record' do
-          expect(UserDevice.add(user_agent, ip, agent.id, fingerprint, other_type))
+          expect(described_class.add(user_agent, ip, agent.id, fingerprint, other_type))
             .to eq(existing_record)
         end
       end
@@ -140,8 +140,8 @@ RSpec.describe UserDevice, type: :model do
         let(:other_user_agent) { '' }
 
         it 'returns a new record' do
-          expect(UserDevice.add(other_user_agent, ip, agent.id, fingerprint, type))
-            .to be_a(UserDevice)
+          expect(described_class.add(other_user_agent, ip, agent.id, fingerprint, type))
+            .to be_a(described_class)
             .and not_eq(existing_record)
         end
       end
@@ -151,7 +151,7 @@ RSpec.describe UserDevice, type: :model do
         let(:other_user_agent) { nil }
 
         it 'returns the original record' do
-          expect(UserDevice.add(other_user_agent, ip, agent.id, fingerprint, type))
+          expect(described_class.add(other_user_agent, ip, agent.id, fingerprint, type))
             .to eq(existing_record)
         end
       end
@@ -161,8 +161,8 @@ RSpec.describe UserDevice, type: :model do
         let(:other_ip) { '176.198.137.254' }
 
         it 'returns a new record' do
-          expect(UserDevice.add(user_agent, other_ip, agent.id, fingerprint, type))
-            .to be_a(UserDevice)
+          expect(described_class.add(user_agent, other_ip, agent.id, fingerprint, type))
+            .to be_a(described_class)
             .and not_eq(existing_record)
         end
       end
@@ -174,14 +174,14 @@ RSpec.describe UserDevice, type: :model do
       let(:type) { 'session' }
 
       it 'raises an error' do
-        expect { UserDevice.add(user_agent, ip, agent.id, fingerprint, type) }
+        expect { described_class.add(user_agent, ip, agent.id, fingerprint, type) }
           .to raise_error(Exceptions::UnprocessableEntity)
       end
     end
   end
 
   describe '.action' do
-    let(:user_device) { UserDevice.add(user_agent, ip, agent.id, fingerprint, type) }
+    let(:user_device) { described_class.add(user_agent, ip, agent.id, fingerprint, type) }
     let(:user_agent) { 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.107 Safari/537.36' }
     let(:ip) { '91.115.248.231' }
     let(:agent) { create(:agent_user) }
@@ -200,7 +200,7 @@ RSpec.describe UserDevice, type: :model do
 
       it 'returns a new user_device' do
         expect(described_class.action(user_device.id, user_agent, other_ip, agent.id, type))
-          .to be_a(UserDevice)
+          .to be_a(described_class)
           .and not_eq(user_device)
       end
     end
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 36e6adf4a..143490d4a 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -177,11 +177,11 @@ RSpec.describe User, type: :model do
 
     describe '.identify' do
       it 'returns users by given login' do
-        expect(User.identify(user.login)).to eq(user)
+        expect(described_class.identify(user.login)).to eq(user)
       end
 
       it 'returns users by given email' do
-        expect(User.identify(user.email)).to eq(user)
+        expect(described_class.identify(user.email)).to eq(user)
       end
     end
   end
@@ -716,7 +716,7 @@ RSpec.describe User, type: :model do
 
     describe '#out_of_office_replacement_id' do
       it 'cannot be set to invalid user ID' do
-        expect { agent.update(out_of_office_replacement_id: User.pluck(:id).max.next) }
+        expect { agent.update(out_of_office_replacement_id: described_class.pluck(:id).max.next) }
           .to raise_error(ActiveRecord::InvalidForeignKey)
       end
 
@@ -980,7 +980,7 @@ RSpec.describe User, type: :model do
     describe 'System-wide agent limit checks:' do
       let(:agent_role) { Role.lookup(name: 'Agent') }
       let(:admin_role) { Role.lookup(name: 'Admin') }
-      let(:current_agents) { User.with_permissions('ticket.agent') }
+      let(:current_agents) { described_class.with_permissions('ticket.agent') }
 
       describe '#validate_agent_limit_by_role' do
         context 'for Integer value of system_agent_limit' do