diff --git a/git-send-email.perl b/git-send-email.perl
index 449d938ba9..734dc9f4f9 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -727,7 +727,7 @@ Date: $date
 Message-Id: $message_id
 X-Mailer: git-send-email $gitversion
 ";
-	if ($thread && $reply_to) {
+	if ($reply_to) {
 
 		$header .= "In-Reply-To: $reply_to\n";
 		$header .= "References: $references\n";