1 files changed, 4 insertions, 2 deletions
diff --git a/app/services/milestones/destroy_service.rb b/app/services/milestones/destroy_service.rb
index e457212508f..600ebcfbecb 100644
--- a/app/services/milestones/destroy_service.rb
+++ b/app/services/milestones/destroy_service.rb
@@ -1,15 +1,17 @@
 module Milestones
   class DestroyService < Milestones::BaseService
     def execute(milestone)
+      return unless milestone.is_project_milestone?
+
       Milestone.transaction do
         update_params = { milestone: nil }
 
         milestone.issues.each do |issue|
-          Issues::UpdateService.new(project, current_user, update_params).execute(issue)
+          Issues::UpdateService.new(parent, current_user, update_params).execute(issue)
         end
 
         milestone.merge_requests.each do |merge_request|
-          MergeRequests::UpdateService.new(project, current_user, update_params).execute(merge_request)
+          MergeRequests::UpdateService.new(parent, current_user, update_params).execute(merge_request)
         end
 
         event_service.destroy_milestone(milestone, current_user)