diff --git a/app/models/mail_handler.rb b/app/models/mail_handler.rb
index 2e25a294f..69e70d21d 100644
--- a/app/models/mail_handler.rb
+++ b/app/models/mail_handler.rb
@@ -74,7 +74,7 @@ class MailHandler < ActionMailer::Base
   cattr_accessor :ignored_emails_headers
   @@ignored_emails_headers = {
     'X-Auto-Response-Suppress' => 'oof',
-    'Auto-Submitted' => /^auto-(replied|generated)/
+    'Auto-Submitted' => /\Aauto-(replied|generated)/
   }
 
   # Processes incoming emails