diff --git a/app/models/merge_requests_closing_issues.rb b/app/models/merge_requests_closing_issues.rb
index 4f093fa27c5..cd49076002d 100644
--- a/app/models/merge_requests_closing_issues.rb
+++ b/app/models/merge_requests_closing_issues.rb
@@ -1,4 +1,9 @@
 class MergeRequestsClosingIssues < ActiveRecord::Base
   belongs_to :merge_request
   belongs_to :issue
+
+  validates_uniqueness_of :merge_request_id, scope: :issue_id
+
+  validates_presence_of :merge_request
+  validates_presence_of :issue
 end