diff --git a/sdrbase/dsp/spectrumvis.cpp b/sdrbase/dsp/spectrumvis.cpp
index 53a384b75..e1347dad8 100644
--- a/sdrbase/dsp/spectrumvis.cpp
+++ b/sdrbase/dsp/spectrumvis.cpp
@@ -893,7 +893,7 @@ void SpectrumVis::applySettings(const SpectrumSettings& settings, bool force)
      || (settings.m_fftOverlap != m_settings.m_fftOverlap) || force)
     {
 		m_overlapSize = settings.m_fftOverlap < 0 ? 0 :
-			settings.m_fftOverlap < fftSize ? settings.m_fftOverlap : (fftSize/2);
+			settings.m_fftOverlap < fftSize ? settings.m_fftOverlap : (fftSize - 1);
         m_refillSize = fftSize - m_overlapSize;
         m_fftBufferFill = m_overlapSize;
     }
diff --git a/sdrgui/gui/glspectrumview.cpp b/sdrgui/gui/glspectrumview.cpp
index 3a41fa565..aaee088cd 100644
--- a/sdrgui/gui/glspectrumview.cpp
+++ b/sdrgui/gui/glspectrumview.cpp
@@ -4450,7 +4450,7 @@ void GLSpectrumView::timeZoom(bool zoomInElseOut)
         return;
     }
 
-    if (zoomInElseOut && (m_fftOverlap == m_fftSize/2)) {
+	if (zoomInElseOut && (m_fftOverlap == m_fftSize - 1)) {
         return;
     }