diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index c66bb1cc06..189e8c8c28 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -1738,7 +1738,7 @@ private:
 	PBD::Signal0<void> EditorFreeze;
 	PBD::Signal0<void> EditorThaw;
 
-	void begin_tempo_map_edit ();
+	Temporal::TempoMap::WritableSharedPtr begin_tempo_map_edit ();
 	void abort_tempo_map_edit ();
 	void mid_tempo_change ();
 
diff --git a/gtk2_ardour/editor_tempodisplay.cc b/gtk2_ardour/editor_tempodisplay.cc
index 387e90f46f..f8678681c1 100644
--- a/gtk2_ardour/editor_tempodisplay.cc
+++ b/gtk2_ardour/editor_tempodisplay.cc
@@ -817,12 +817,12 @@ Editor::real_remove_meter_marker (Temporal::MeterPoint const * section)
 	return FALSE;
 }
 
-void
+Temporal::TempoMap::WritableSharedPtr
 Editor::begin_tempo_map_edit ()
 {
-	TempoMap::fetch_writable ();
-	TempoMap::SharedPtr tmap (TempoMap::use());
-	reassociate_metric_markers (tmap);
+	TempoMap::WritableSharedPtr wmap = TempoMap::fetch_writable ();
+	reassociate_metric_markers (wmap);
+	return wmap;
 }
 
 void