diff --git a/gtk2_ardour/pianoroll.cc b/gtk2_ardour/pianoroll.cc
index 3bacfb0b6e..0e466f2e00 100644
--- a/gtk2_ardour/pianoroll.cc
+++ b/gtk2_ardour/pianoroll.cc
@@ -243,7 +243,13 @@ Pianoroll::add_multi_controller_item (Gtk::Menu_Helpers::MenuList&,
 void
 Pianoroll::layered_automation_button_clicked ()
 {
-	if ((layered_automation = !layered_automation)) {
+	set_layered_automation (!layered_automation);
+}
+
+void
+Pianoroll::set_layered_automation (bool yn)
+{
+	if ((layered_automation = yn)) {
 		layered_automation_button->set_active_state (Gtkmm2ext::ExplicitActive);
 		if (view && view->n_visible_automation() > 1) {
 			view->hide_all_automation ();
diff --git a/gtk2_ardour/pianoroll.h b/gtk2_ardour/pianoroll.h
index c2ea199e23..f385669b97 100644
--- a/gtk2_ardour/pianoroll.h
+++ b/gtk2_ardour/pianoroll.h
@@ -167,6 +167,8 @@ class Pianoroll : public CueEditor
 	bool key_press_handler (ArdourCanvas::Item*, GdkEvent*, ItemType);
 	bool key_release_handler (ArdourCanvas::Item*, GdkEvent*, ItemType);
 
+	void set_layered_automation (bool);
+
 	void escape ();
 	void session_going_away ();