diff --git a/libs/ardour/ardour/midi_source.h b/libs/ardour/ardour/midi_source.h
index 8343bbd177..4ae355574b 100644
--- a/libs/ardour/ardour/midi_source.h
+++ b/libs/ardour/ardour/midi_source.h
@@ -26,7 +26,6 @@
 #include <string>
 #include <time.h>
 #include <glibmm/threads.h>
-#include <boost/enable_shared_from_this.hpp>
 
 #include "pbd/stateful.h"
 #include "pbd/xml++.h"