diff --git a/MainWindow.h b/MainWindow.h
index 592cf78..5872cbc 100644
--- a/MainWindow.h
+++ b/MainWindow.h
@@ -33,7 +33,7 @@
 #include "Tone.h"
 #include "ColorScale.h"
 #include "CircleOfFifths.h"
-
+#include "MidiProbe.h"
 
 class MainWindow : public QMainWindow
 {