diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..949b86c
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,24 @@
+name: Tests
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    services:
+      redis:
+        image: redis:8-alpine
+        ports:
+          - 16379:6379
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 1s
+          --health-timeout 5s
+          --health-retries 10
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '3.4'
+          bundler-cache: true
+      - run: bundle exec rake
diff --git a/.gitignore b/.gitignore
index 9b87472..8c6efc7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 Gemfile.lock
 *.gem
 gemfiles/
+coverage/
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 8b4f32b..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-language: ruby
-services:
-  - redis-server
-rvm:
- - 3.0.1
-script:
-  - bundle exec rake test
diff --git a/README.md b/README.md
index a7e414f..37663ee 100644
--- a/README.md
+++ b/README.md
@@ -43,6 +43,9 @@ Check [the code](lib/sidekiq/repeat/mini_ice_cube.rb) for documentation.
 # setup
 bundle install
 
+# Start Redis in another terminal (or use an existing instance)
+docker run --rm -p 127.0.0.1:16379:6379 redis:8-alpine
+
 # Run the tests
 bundle exec rake test
 
diff --git a/Rakefile b/Rakefile
index db43587..4288f83 100644
--- a/Rakefile
+++ b/Rakefile
@@ -4,3 +4,5 @@ Rake::TestTask.new(:test) do |test|
   test.libs << 'test'
   test.pattern = 'test/**/*.rb'
 end
+
+task default: :test
diff --git a/lib/sidekiq/repeat/configuration.rb b/lib/sidekiq/repeat/configuration.rb
index 0031e12..1e186e9 100644
--- a/lib/sidekiq/repeat/configuration.rb
+++ b/lib/sidekiq/repeat/configuration.rb
@@ -19,8 +19,8 @@ def reset_to_default!
 
       def self.with_lock
         if instance.redlock_enabled
-          Redlock::Client.new(instance.redlock_redis_instances).lock('sidekiq-repeat-reschedule-all', 500) do
-            yield
+          Redlock::Client.new(instance.redlock_redis_instances).lock('sidekiq-repeat-reschedule-all', 500) do |lock_info|
+            yield if lock_info
           end
         else
           yield
diff --git a/sidekiq-repeat.gemspec b/sidekiq-repeat.gemspec
index 5c0ce1d..9a2d04a 100644
--- a/sidekiq-repeat.gemspec
+++ b/sidekiq-repeat.gemspec
@@ -14,11 +14,14 @@ Gem::Specification.new do |spec|
   spec.files         = Dir['lib/**/*rb']
   spec.require_paths = ['lib']
 
-  spec.add_dependency 'sidekiq', '>= 6', '< 7.0'
-  spec.add_dependency 'parse-cron', '~> 0.1'
-  spec.add_dependency 'redlock', '~> 1'
+  spec.add_dependency 'sidekiq', '~> 8', '< 9'
+  spec.add_dependency 'parse-cron', '~> 0.1.4'
+  spec.add_dependency 'redlock', '~> 2'
+  # Sidekiq 6.5 requires these libraries without declaring them as gems.
+  spec.add_dependency 'base64', '~> 0.3'
+  spec.add_dependency 'logger', '~> 1.7'
 
-  spec.add_development_dependency 'minitest', '~> 3'
-  spec.add_development_dependency 'rake', '>= 12.3.3'
-  spec.add_development_dependency 'redis-namespace', '~> 1.3'
+  spec.add_development_dependency 'minitest', '~> 5.25'
+  spec.add_development_dependency 'rake', '~> 13.3'
+  spec.add_development_dependency 'simplecov', '~> 1.0'
 end
diff --git a/test/mini_ice_cube.rb b/test/mini_ice_cube.rb
index 5bdddad..de1039e 100644
--- a/test/mini_ice_cube.rb
+++ b/test/mini_ice_cube.rb
@@ -1,7 +1,6 @@
-require 'minitest/autorun'
-require 'sidekiq/repeat/mini_ice_cube'
+require_relative 'test_helper'
 
-class TestMiniIceCube < MiniTest::Unit::TestCase
+class TestMiniIceCube < Minitest::Test
   def setup
     @dsl = Sidekiq::Repeat::MiniIceCube::MainDsl.new
   end
diff --git a/test/repeat.rb b/test/repeat.rb
index 64dbf26..24a2b2d 100644
--- a/test/repeat.rb
+++ b/test/repeat.rb
@@ -1,8 +1,6 @@
-require 'minitest/autorun'
+require_relative 'test_helper'
 
-require_relative './test_helper.rb'
-
-class TestRescheduling < MiniTest::Unit::TestCase
+class TestRescheduling < Minitest::Test
   include TestHelper.assertions('SidekiqRepeatTestJob')
   include TestHelper.application_setup
 
@@ -53,7 +51,7 @@ def test_reschedules_job_if_in_the_future
   end
 end
 
-class TestArguments < MiniTest::Unit::TestCase
+class TestArguments < Minitest::Test
   include TestHelper.assertions('SidekiqRepeatArgumentsTestJob', true)
   include TestHelper.application_setup
 
@@ -64,16 +62,20 @@ def test_perform_called_with_parameters
   end
 end
 
-class TestRedlockDefaultConfiguration < MiniTest::Unit::TestCase
+class TestRedlockDefaultConfiguration < Minitest::Test
   include TestHelper.assertions('SidekiqRepeatTestJob')
   include TestHelper.application_setup(false)
 
   def test_startup_scheduling_is_locked
-    expect_redlock! { startup_sidekiq! }
+    with_redlock_held { startup_sidekiq! }
+    assert_not_scheduled
+
+    startup_sidekiq!
+    assert_scheduled
   end
 end
 
-class TestRedlockDisabled < MiniTest::Unit::TestCase
+class TestRedlockDisabled < Minitest::Test
   include TestHelper.assertions('SidekiqRepeatTestJob')
   include TestHelper.application_setup(false)
 
@@ -82,19 +84,21 @@ def configure(config)
   end
 
   def test_startup_scheduling_is_not_locked
-    expect_no_redlock! { startup_sidekiq! }
+    with_redlock_held { startup_sidekiq! }
+    assert_scheduled
   end
 end
 
-class TestRedlockMultipleRedisInstances < MiniTest::Unit::TestCase
+class TestRedlockMultipleRedisInstances < Minitest::Test
   include TestHelper.assertions('SidekiqRepeatTestJob')
   include TestHelper.application_setup(false)
 
   def configure(config)
-    config.redlock_redis_instances = ['redis://1.2.3.4/', 'redis://5.6.7.8/']
+    config.redlock_redis_instances = [Sidekiq.redis_pool, TestHelper.second_redis_pool]
   end
 
-  def test_startup_scheduling_is_not_locked
-    expect_redlock!(['redis://1.2.3.4/', 'redis://5.6.7.8/']) { startup_sidekiq! }
+  def test_startup_scheduling_is_locked
+    with_redlock_held(TestHelper.second_redis_pool) { startup_sidekiq! }
+    assert_not_scheduled
   end
 end
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 95b4217..3ab91e5 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,15 +1,32 @@
 # This test setup was taken from sidekiq-middleware:
 # https://github.com/krasnoukhov/sidekiq-middleware/blob/v0.3.0/test/test_unique_jobs.rb
 
+require 'simplecov'
+SimpleCov.start do
+  cover 'lib/**/*.rb'
+end
+
+require 'minitest/autorun'
 require 'sidekiq'
 require 'sidekiq/cli'
-require 'sidekiq/processor'
-require 'sidekiq/redis_connection'
+require 'minitest/mock'
+
+Sidekiq.testing!(:disable)
 Sidekiq.logger.level = Logger::ERROR
-Sidekiq.redis = Sidekiq::RedisConnection.create(:namespace => 'sidekiq-repeat-test')
+configure_sidekiq = proc do |config|
+  config.redis = {
+    url: ENV.fetch('TEST_REDIS_URL', 'redis://127.0.0.1:16379')
+  }
+end
+Sidekiq.configure_client(&configure_sidekiq)
+Sidekiq.configure_server(&configure_sidekiq)
 
 require 'sidekiq-repeat'
 
+Sidekiq::Testing.server_middleware do |chain|
+  chain.add Sidekiq::Repeat::Middleware
+end
+
 class SidekiqRepeatTestJob
   include Sidekiq::Worker
   include Sidekiq::Repeat::Repeatable
@@ -33,13 +50,17 @@ def perform(last, current)
   end
 end
 
-UnitOfWork = Struct.new(:queue, :job) do
-  def acknowledge; end
-  def queue_name; end
-  def requeue; end
-end
-
 module TestHelper
+  LOCK_KEY = 'sidekiq-repeat-reschedule-all'
+
+  def self.second_redis_pool
+    @second_redis_pool ||= begin
+      primary_db = Sidekiq.redis { |redis| redis.config.db }
+      client = RedisClient.config(url: ENV.fetch('TEST_REDIS_URL', 'redis://127.0.0.1:16379'), db: primary_db == 1 ? 0 : 1)
+      client.new_pool(size: 1)
+    end
+  end
+
   def self.assertions(klass, perform_with_arguments = false)
     Module.new do
       # NOTE: For some reason, we need to use define_method here, as otherwise `klass`
@@ -80,64 +101,61 @@ def delete_scheduled!
       scheduled_jobs.map(&:delete)
     end
 
+    # Enqueues a job in memory with +fake!+, then executes it with +perform_one+, the purpose is to only use public
+    # Sidekiq API. During execution, testing is disabled, so the middleware schedules the next occurrence in Redis.
     def perform_scheduled!
-      msg = Sidekiq.dump_json('class' => klass_name, 'queue' => 'default', 'args' => perform_args)
-      work = UnitOfWork.new('default', msg)
-      actor = MiniTest::Mock.new
-      actor.expect(:processor_done, nil, [@processor])
-      2.times { @boss.expect(:async, actor, []) }
-      @processor.send(:process, work)
+      worker = Object.const_get(klass_name)
+      Sidekiq::Testing.fake! { worker.perform_async(*perform_args) }
+      worker.perform_one
     end
 
-    def expect_redlock!(redis_instances = nil)
-      redis_instances ||= Sidekiq::Repeat::Configuration.instance.redlock_redis_instances
+    def with_redlock_held(redis = Sidekiq.redis_pool)
+      client = Redlock::Client.new([redis], retry_count: 0)
+      lock = client.lock(TestHelper::LOCK_KEY, 30_000)
+      raise 'Could not acquire test lock' unless lock
 
-      @redlock_client_instance = MiniTest::Mock.new
-      @redlock_client_instance.expect(:lock, nil, ['sidekiq-repeat-reschedule-all', 500])
-
-      @redlock_client_new_method = MiniTest::Mock.new
-      @redlock_client_new_method.expect(:call, @redlock_client_instance, [redis_instances])
-
-      Redlock::Client.stub(:new, @redlock_client_new_method) do
-        yield  # to test case.
-      end
-
-      @redlock_client_new_method.verify
-      @redlock_client_instance.verify
-    end
-
-    def expect_no_redlock!
-      @redlock_client_new_method = Proc.new { flunk 'Redlock::Client::new should not be called' }
-      Redlock::Client.stub(:new, @redlock_client_new_method) do
-        yield
-      end
+      yield
+    ensure
+      client.unlock(lock) if lock
     end
   end
 
   module ApplicationSetup
+    def run
+      Time.stub(:now, Time.local(2030, 1, 2, 12, 10, 30)) { super }
+    end
+
     def configure(config)
       # To be overwritten in test class.
     end
 
     def setup
+      clear_test_redis
+      Sidekiq::Repeat::Repeatable.repeatables.each do |klass|
+        klass.repeat { hourly }
+        klass.instance_variable_set(:@cronline, nil)
+        klass.instance_variable_set(:@ss, nil)
+      end
+      Sidekiq::Repeat::Configuration.instance.redlock_redis_instances = [Sidekiq.redis_pool]
       # Allow the test to configure Sidekiq::Repeat.
       Sidekiq::Repeat.configure { |config| configure(config) }
 
-      @boss = MiniTest::Mock.new
-      2.times { @boss.expect(:options, {:queues => ['default'] }, []) }
-      @processor = Sidekiq::Processor.new(@boss, queues: ['default'])
       startup_sidekiq! if startup_sidekiq
     end
 
     def teardown
+      clear_test_redis
       # Reset to defaults for next test case.
       Sidekiq::Repeat::Configuration.instance.reset_to_default!
     end
 
     def startup_sidekiq!
-      events = Sidekiq.options[:lifecycle_events][:startup].dup
-      @processor.fire_event(:startup)
-      Sidekiq.options[:lifecycle_events][:startup] = events
+      Sidekiq.default_configuration[:lifecycle_events][:startup].each(&:call)
+    end
+
+    def clear_test_redis
+      Sidekiq.redis(&:flushdb)
+      TestHelper.second_redis_pool.with { |redis| redis.call('DEL', TestHelper::LOCK_KEY) }
     end
   end
 end