diff --git a/libs/ardour/midi_ui.cc b/libs/ardour/midi_ui.cc
index 0729132d6c..b80370ec6a 100644
--- a/libs/ardour/midi_ui.cc
+++ b/libs/ardour/midi_ui.cc
@@ -61,6 +61,8 @@ MidiControlUI::do_request (MidiUIRequest* req)
 {
 	if (req->type == Quit) {
 		BaseUI::quit ();
+	} else if (req->type == CallSlot) {
+		req->the_slot ();
 	}
 }