diff --git a/sdrbase/dsp/spectrumvis.cpp b/sdrbase/dsp/spectrumvis.cpp
index fd22bce99..bace59666 100644
--- a/sdrbase/dsp/spectrumvis.cpp
+++ b/sdrbase/dsp/spectrumvis.cpp
@@ -67,6 +67,7 @@ SpectrumVis::SpectrumVis(Real scalef) :
     m_sampleRate(48000),
 	m_ofs(0),
     m_powFFTDiv(1.0),
+    m_guiMessageQueue(nullptr),
 	m_mutex(QMutex::Recursive)
 {
 	setObjectName("SpectrumVis");