diff --git a/mainwindow.cpp b/mainwindow.cpp
index cc782b2c1..31e4519e5 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -4498,7 +4498,9 @@ void MainWindow::genStdMsgs(QString rpt, bool unconditional)
        if(m_config.bRTTYroundup()) {
         t=t0 + rst + m_config.RTTYExchange();             //Use a real report
         msgtype(t, ui->tx2);
-        t=t0 + "R " + rst + m_config.RTTYExchange();
+        QString t1=m_config.RTTYExchange();
+        if(t1=="DX" or t1=="#") t1.sprintf("%4.4d",ui->sbSerialNumber->value());
+        t=t0 + "R " + rst + t1;
         msgtype(t, ui->tx3);
         m_send_RR73=true;
       }