diff --git a/master.cfg b/master.cfg
index 49ba5c1..7efdd91 100644
--- a/master.cfg
+++ b/master.cfg
@@ -297,7 +297,7 @@ subsequent commits are made after X, by different people."""
     bf.close ()
 
     SendRootBreakageMessage (name, branch, change)
-    root_message_id = make_breakage_root_message_id (rev, branch)
+    root_message_id = make_breakage_root_message_id (change.revision, branch)
 
     rev = change.revision
     to = change.who.encode ('ascii', 'ignore').decode ('ascii')