diff --git a/gtk2_ardour/route_properties_box.cc b/gtk2_ardour/route_properties_box.cc
index f5248b3b61..e527444386 100644
--- a/gtk2_ardour/route_properties_box.cc
+++ b/gtk2_ardour/route_properties_box.cc
@@ -103,12 +103,20 @@ RoutePropertiesBox::set_session (ARDOUR::Session* s) {
 	_insert_frame.add (*_insert_box);
 	_insert_frame.set_padding (4);
 	_insert_frame.set_size_request (144 * ui_scale, 236 * ui_scale);
+
+	_session->SurroundMasterAddedOrRemoved.connect (_session_connections, invalidator (*this), std::bind (&RoutePropertiesBox::surround_master_added_or_removed, this), gui_context());
 }
 
 void
-RoutePropertiesBox::set_route (std::shared_ptr<Route> r)
+RoutePropertiesBox::surround_master_added_or_removed ()
 {
-	if (r == _route) {
+	set_route (_route, true);
+}
+
+void
+RoutePropertiesBox::set_route (std::shared_ptr<Route> r, bool force_update)
+{
+	if (r == _route && !force_update) {
 		return;
 	}
 
diff --git a/gtk2_ardour/route_properties_box.h b/gtk2_ardour/route_properties_box.h
index 2bbe4b9c6e..cd26734dcc 100644
--- a/gtk2_ardour/route_properties_box.h
+++ b/gtk2_ardour/route_properties_box.h
@@ -46,7 +46,7 @@ public:
 	~RoutePropertiesBox ();
 
 	void set_session (ARDOUR::Session*);
-	void set_route (std::shared_ptr<ARDOUR::Route>);
+	void set_route (std::shared_ptr<ARDOUR::Route>, bool force = false);
 
 private:
 	void property_changed (const PBD::PropertyChange& what_changed);
@@ -59,6 +59,7 @@ private:
 	void refill_processors ();
 	void add_processor_to_display (std::weak_ptr<ARDOUR::Processor> w);
 	void idle_refill_processors ();
+	void surround_master_added_or_removed ();
 
 	static int _idle_refill_processors (gpointer);