diff --git a/master.cfg b/master.cfg
index 64d9d65..0f105cd 100644
--- a/master.cfg
+++ b/master.cfg
@@ -202,7 +202,7 @@ def SendRootMessageGDBTesters (branch, change, rev,
     else:
         mail['To'] = try_to
         mailto = try_to
-        mail['Message-Id'] = "<%s-try-%d@gdb-build>" % (rev, count)
+        mail['Message-Id'] = "<%s-try-%s@gdb-build>" % (rev, try_count)
 
     s = smtplib.SMTP ('localhost')
     s.sendmail (GDB_MAIL_FROM, [ mailto ], mail.as_string ())