diff --git a/gtk2_ardour/midi_region_view.cc b/gtk2_ardour/midi_region_view.cc
index 97bc7ca630..25254e6bc2 100644
--- a/gtk2_ardour/midi_region_view.cc
+++ b/gtk2_ardour/midi_region_view.cc
@@ -969,6 +969,9 @@ MidiRegionView::redisplay_model()
 		}
 	}
 
+	_pgm_changes.clear();
+	_sys_exes.clear();
+	
 	display_sysexes();
 	display_program_changes();