diff --git a/sdrgui/gui/glspectrum.cpp b/sdrgui/gui/glspectrum.cpp
index 112bed8bd..43239d058 100644
--- a/sdrgui/gui/glspectrum.cpp
+++ b/sdrgui/gui/glspectrum.cpp
@@ -250,6 +250,15 @@ void GLSpectrum::setTimingRate(qint32 timingRate)
     update();
 }
 
+void GLSpectrum::setFFTOverlap(int overlap)
+{
+    m_mutex.lock();
+    m_fftOverlap = overlap;
+    m_changesPending = true;
+	m_mutex.unlock();
+    update();
+}
+
 void GLSpectrum::setDisplayWaterfall(bool display)
 {
     m_mutex.lock();
@@ -1292,6 +1301,8 @@ void GLSpectrum::applyChanges()
 		if (m_sampleRate > 0)
 		{
 			float scaleDiv = ((float)m_sampleRate / (float)m_timingRate) * (m_ssbSpectrum ? 2 : 1);
+			float halfFFTSize = m_fftSize / 2;
+			scaleDiv *= halfFFTSize / (halfFFTSize - m_fftOverlap);
 
 			if (!m_invertedWaterfall) {
 				m_timeScale.setRange(m_timingRate > 1 ? Unit::TimeHMS : Unit::Time, (m_waterfallHeight * m_fftSize) / scaleDiv, 0);
@@ -1393,6 +1404,8 @@ void GLSpectrum::applyChanges()
 		if (m_sampleRate > 0)
 		{
 			float scaleDiv = ((float)m_sampleRate / (float)m_timingRate) * (m_ssbSpectrum ? 2 : 1);
+			float halfFFTSize = m_fftSize / 2;
+			scaleDiv *= halfFFTSize / (halfFFTSize - m_fftOverlap);
 
 			if (!m_invertedWaterfall) {
 				m_timeScale.setRange(m_timingRate > 1 ? Unit::TimeHMS : Unit::Time, (m_waterfallHeight * m_fftSize) / scaleDiv, 0);
diff --git a/sdrgui/gui/glspectrum.h b/sdrgui/gui/glspectrum.h
index d9e31ce67..63613e3c7 100644
--- a/sdrgui/gui/glspectrum.h
+++ b/sdrgui/gui/glspectrum.h
@@ -80,6 +80,7 @@ public:
 	void setCenterFrequency(qint64 frequency);
 	void setSampleRate(qint32 sampleRate);
 	void setTimingRate(qint32 timingRate);
+    void setFFTOverlap(int overlap);
 	void setReferenceLevel(Real referenceLevel);
 	void setPowerRange(Real powerRange);
 	void setDecay(int decay);
@@ -248,6 +249,7 @@ private:
 	int m_decay;
 	quint32 m_sampleRate;
 	quint32 m_timingRate;
+    int m_fftOverlap;
 
 	int m_fftSize;
 
diff --git a/sdrgui/gui/glspectrumgui.cpp b/sdrgui/gui/glspectrumgui.cpp
index 2b07d1542..7090de2be 100644
--- a/sdrgui/gui/glspectrumgui.cpp
+++ b/sdrgui/gui/glspectrumgui.cpp
@@ -522,6 +522,10 @@ void GLSpectrumGUI::setMaximumOverlap()
     ui->fftOverlap->setMaximum((m_settings.m_fftSize/2)-1);
     int value = ui->fftOverlap->value();
     ui->fftOverlapText->setText(tr("%1").arg(value));
+
+    if (m_glSpectrum) {
+        m_glSpectrum->setFFTOverlap(value);
+    }
 }
 
 bool GLSpectrumGUI::handleMessage(const Message& message)