diff --git a/modules/gitlab_integration/app/workers/cron/clear_old_merge_requests_job.rb b/modules/gitlab_integration/app/workers/cron/clear_old_merge_requests_job.rb
index fa30113be3af..5a588b4a75d9 100644
--- a/modules/gitlab_integration/app/workers/cron/clear_old_merge_requests_job.rb
+++ b/modules/gitlab_integration/app/workers/cron/clear_old_merge_requests_job.rb
@@ -30,9 +30,12 @@
 #++
 
 module Cron
-  class ClearOldMergeRequestsJob < ApplicationJob
+  class ClearOldMergeRequestsJob < CronJob
     priority_number :low
 
+    # runs at 1:25 nightly
+    self.cron_expression = "25 1 * * *"
+
     def perform
       GitlabMergeRequest.without_work_package
                        .find_each(&:destroy!)
diff --git a/modules/gitlab_integration/lib/open_project/gitlab_integration/engine.rb b/modules/gitlab_integration/lib/open_project/gitlab_integration/engine.rb
index 48b2c0b84582..89377b7981ff 100644
--- a/modules/gitlab_integration/lib/open_project/gitlab_integration/engine.rb
+++ b/modules/gitlab_integration/lib/open_project/gitlab_integration/engine.rb
@@ -100,13 +100,9 @@ class Engine < ::Rails::Engine
       mount ::API::V3::GitlabIssues::GitlabIssuesByWorkPackageAPI
     end
 
-    add_cron_jobs do
-      {
-        "Cron::ClearOldMergeRequestsJob": {
-          cron: "25 1 * * *", # runs at 1:25 nightly
-          class: ::Cron::ClearOldMergeRequestsJob.name
-        }
-      }
+    config.to_prepare do
+      # Register the cron job to clean up old gitlab merge requests
+      ::Cron::CronJob.register! ::Cron::ClearOldMergeRequestsJob
     end
   end
 end