diff --git a/server/client.go b/server/client.go
index 3c3a6d5eed2..5099969be15 100644
--- a/server/client.go
+++ b/server/client.go
@@ -4051,7 +4051,8 @@ func (c *client) processInboundClientMsg(msg []byte) (bool, bool) {
 		c.mu.Lock()
 		if c.opts.NoResponders {
 			if sub := c.subForReply(c.pa.reply); sub != nil {
-				proto := fmt.Sprintf("HMSG %s %s 16 16\r\nNATS/1.0 503\r\n\r\n\r\n", c.pa.reply, sub.sid)
+				hdrLen := 32 /* header without the subject */ + len(c.pa.subject)
+				proto := fmt.Sprintf("HMSG %s %s %d %d\r\nNATS/1.0 503\r\nNats-Subject: %s\r\n\r\n\r\n", c.pa.reply, sub.sid, hdrLen, hdrLen, c.pa.subject)
 				c.queueOutbound([]byte(proto))
 				c.addToPCD(c)
 			}
diff --git a/server/client_test.go b/server/client_test.go
index a0a17799e67..4fadfbd73b6 100644
--- a/server/client_test.go
+++ b/server/client_test.go
@@ -252,7 +252,7 @@ func TestClientNoResponderSupport(t *testing.T) {
 	if len(am) == 0 {
 		t.Fatalf("Did not get a match for %q", l)
 	}
-	checkPayload(cr, []byte("NATS/1.0 503\r\n\r\n"), t)
+	checkPayload(cr, []byte("NATS/1.0 503\r\nNats-Subject: foo\r\n\r\n\r\n"), t)
 }
 
 func TestServerHeaderSupport(t *testing.T) {