diff -burN qtractor-0.7.0.orig/src/qtractorCurve.h qtractor-0.7.0/src/qtractorCurve.h
--- qtractor-0.7.0.orig/src/qtractorCurve.h	2015-07-25 06:06:44.869457637 +0800
+++ qtractor-0.7.0/src/qtractorCurve.h	2015-08-02 23:44:59.664835605 +0800
@@ -26,7 +26,7 @@
 #include "qtractorMidiSequence.h"
 
 #include <QColor>
-
+#include <QObject>
 
 // Forward declarations.
 class qtractorTimeScale;
diff -burN qtractor-0.7.0.orig/src/qtractorMidiEngine.h qtractor-0.7.0/src/qtractorMidiEngine.h
--- qtractor-0.7.0.orig/src/qtractorMidiEngine.h	2015-07-25 06:06:44.887457637 +0800
+++ qtractor-0.7.0/src/qtractorMidiEngine.h	2015-08-02 23:45:24.057834421 +0800
@@ -30,6 +30,7 @@
 #include <alsa/asoundlib.h>
 
 #include <QHash>
+#include <QObject>
 
 // Forward declarations.
 class qtractorMidiBus;
diff -burN qtractor-0.7.0.orig/src/qtractorMidiTimer.h qtractor-0.7.0/src/qtractorMidiTimer.h
--- qtractor-0.7.0.orig/src/qtractorMidiTimer.h	2015-07-25 06:06:44.890457637 +0800
+++ qtractor-0.7.0/src/qtractorMidiTimer.h	2015-08-02 23:45:44.008833452 +0800
@@ -23,7 +23,7 @@
 #define __qtractorMidiTimer_h
 
 #include <QStringList>
-
+#include <QObject>
 
 //----------------------------------------------------------------------
 // class qtractorMidiTimer -- ALSA sequencer timer stuff (singleton).
diff -burN qtractor-0.7.0.orig/src/qtractorTimeScale.h qtractor-0.7.0/src/qtractorTimeScale.h
--- qtractor-0.7.0.orig/src/qtractorTimeScale.h	2015-07-25 06:06:44.900457637 +0800
+++ qtractor-0.7.0/src/qtractorTimeScale.h	2015-08-02 23:46:02.666832546 +0800
@@ -26,7 +26,7 @@
 
 #include <QStringList>
 #include <QColor>
-
+#include <QObject>
 
 //----------------------------------------------------------------------
 // class qtractorTimeScale -- Time scale conversion helper class.