diff --git a/spectrogramplot.cpp b/spectrogramplot.cpp
index d7a0f2a..a756bed 100644
--- a/spectrogramplot.cpp
+++ b/spectrogramplot.cpp
@@ -31,7 +31,7 @@
 #include "util.h"
 
 
-SpectrogramPlot::SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float>>> src) : Plot(src), inputSource(src), tuner(this)
+SpectrogramPlot::SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float>>> src) : Plot(src), inputSource(src), fftSize(512), tuner(this)
 {
     setFFTSize(512);
     zoomLevel = 1;