diff --git a/widgets/mainwindow.cpp b/widgets/mainwindow.cpp
index 7262f2e12..f7c5476eb 100644
--- a/widgets/mainwindow.cpp
+++ b/widgets/mainwindow.cpp
@@ -7042,7 +7042,7 @@ void MainWindow::setFreq4(int rxFreq, int txFreq)
   } else {
     if (ui->TxFreqSpinBox->isEnabled ()) {
       ui->TxFreqSpinBox->setValue(txFreq);
-      if ("FT8" == m_mode || "FT4" == m_mode)
+      if ("FT8" == m_mode || "FT4" == m_mode || m_mode=="FST4")
         {
           // we need to regenerate the current transmit waveform for
           // GFSK modulated modes