diff --git a/libs/ardour/triggerbox.cc b/libs/ardour/triggerbox.cc
index defc5b53ac..ff188bb6df 100644
--- a/libs/ardour/triggerbox.cc
+++ b/libs/ardour/triggerbox.cc
@@ -1722,6 +1722,7 @@ AudioTrigger::set_region_in_worker_thread_internal (std::shared_ptr<Region> r, b
 
 	if (!r) {
 		data.reset ();
+		send_property_change (ARDOUR::Properties::region);
 		return 0;
 	}
 
@@ -2987,6 +2988,7 @@ MIDITrigger::set_region_in_worker_thread (std::shared_ptr<Region> r)
 		delete old;
 		_model.reset ();
 		set_name ("");
+		send_property_change (ARDOUR::Properties::region);
 		return 0;
 	}