diff --git a/git-codereview/mail.go b/git-codereview/mail.go
index 3e63203..4a2b973 100644
--- a/git-codereview/mail.go
+++ b/git-codereview/mail.go
@@ -86,7 +86,7 @@
 	// There is no conflict with the branch names people are using
 	// for work, because git change rejects any name containing a dot.
 	// The space of names with dots is ours (the Go team's) to define.
-	run("git", "tag", "-f", b.Name+".mailed")
+	run("git", "tag", "-f", b.Name+".mailed", c.ShortHash)
 }
 
 // PushSpec returns the spec for a Gerrit push command to publish the change c in b.