diff --git a/gtk2_ardour/note_select_dialog.h b/gtk2_ardour/note_select_dialog.h
index 607dbe1506..910728f2fb 100644
--- a/gtk2_ardour/note_select_dialog.h
+++ b/gtk2_ardour/note_select_dialog.h
@@ -20,6 +20,7 @@
 #ifndef __gtk2_ardour_note_select_dialog_h__
 #define __gtk2_ardour_note_select_dialog_h__
 
+#include <stdint.h>
 #include "ardour_dialog.h"
 #include "gtk_pianokeyboard.h"