diff --git a/app/models/project_services/jira_service.rb b/app/models/project_services/jira_service.rb
index 7ab79242cc3..d08fcd8954d 100644
--- a/app/models/project_services/jira_service.rb
+++ b/app/models/project_services/jira_service.rb
@@ -31,7 +31,7 @@ class JiraService < IssueTrackerService
 
   # {PROJECT-KEY}-{NUMBER} Examples: JIRA-1, PROJECT-1
   def self.reference_pattern(only_long: true)
-    @reference_pattern ||= /(?<issue>\b([A-Z][A-Z0-9_]+-)\d+)/
+    @reference_pattern ||= /(?<issue>\b#{Gitlab::Regex.jira_issue_key_regex})/
   end
 
   def initialize_properties
diff --git a/lib/gitlab/regex.rb b/lib/gitlab/regex.rb
index e43147a3f37..21614ea003e 100644
--- a/lib/gitlab/regex.rb
+++ b/lib/gitlab/regex.rb
@@ -94,6 +94,12 @@ module Gitlab
       }mx
     end
 
+    # Based on Jira's project key format
+    # https://confluence.atlassian.com/adminjiraserver073/changing-the-project-key-format-861253229.html
+    def jira_issue_key_regex
+      @jira_issue_key_regex ||= /[A-Z][A-Z_0-9]+-\d+/
+    end
+
     def jira_transition_id_regex
       @jira_transition_id_regex ||= /\d+/
     end