diff --git a/test/unit/mail_handler_test.rb b/test/unit/mail_handler_test.rb
index 96d16d8..317c3bc 100644
--- a/test/unit/mail_handler_test.rb
+++ b/test/unit/mail_handler_test.rb
@@ -67,6 +67,7 @@ class MailHandlerTest < ActiveSupport::TestCase
     # Email notification should be sent
     mail = ActionMailer::Base.deliveries.last
     assert_not_nil mail
+    assert mail.subject.include?("##{issue.id}")
     assert mail.subject.include?('New ticket on a given project')
   end