Index: include/MidiSndio.h
--- include/MidiSndio.h.orig
+++ include/MidiSndio.h
@@ -32,6 +32,7 @@
 
 #include <QtCore/QThread>
 #include <QtCore/QFile>
+#include <QtCore/QMutex>
 
 #include <sndio.h>
 
@@ -64,6 +65,7 @@ class MidiSndio : public MidiClientRaw, public QThread
 	virtual void run(void);
 
 private:
+	QMutex m_hdlMutex;
 	struct mio_hdl *m_hdl;
 	volatile bool m_quit;
 } ;
