diff --git a/src/applications/gqrx/mainwindow.cpp b/src/applications/gqrx/mainwindow.cpp
index bb14e27e1..8f16630f8 100644
--- a/src/applications/gqrx/mainwindow.cpp
+++ b/src/applications/gqrx/mainwindow.cpp
@@ -68,6 +68,7 @@ MainWindow::MainWindow(const QString& cfgfile, bool edit_conf, QWidget *parent)
     d_lnb_lo(0),
     d_hw_freq(0),
     d_fftAvg(0.25),
+    d_fftWindowType(0),
     d_fftNormalizeEnergy(false),
     d_have_audio(true),
     dec_afsk1200(nullptr)