diff --git a/gtk2_ardour/editor_ops.cc b/gtk2_ardour/editor_ops.cc
index 0e2a641e0c..990d59b00e 100644
--- a/gtk2_ardour/editor_ops.cc
+++ b/gtk2_ardour/editor_ops.cc
@@ -9581,10 +9581,9 @@ Editor::temporal_zoom_extents ()
 void
 Editor::edit_region_in_pianoroll_window ()
 {
-	selection->foreach_midi_regionview (&MidiRegionView::edit_in_pianoroll_window);
+	selection->foreach_midi_regionview (&MidiRegionView::show_region_editor);
 }
 
-
 void
 Editor::find_and_display_track ()
 {
diff --git a/gtk2_ardour/midi_region_view.cc b/gtk2_ardour/midi_region_view.cc
index 39959d1b11..8f3d7049c5 100644
--- a/gtk2_ardour/midi_region_view.cc
+++ b/gtk2_ardour/midi_region_view.cc
@@ -701,23 +701,6 @@ MidiRegionView::add_control_points_to_selection (timepos_t const & start, timepo
 	}
 }
 
-void
-MidiRegionView::edit_in_pianoroll_window ()
-{
-	std::shared_ptr<MidiTrack> track = std::dynamic_pointer_cast<MidiTrack> (trackview.stripable());
-	assert (track);
-
-	PianorollWindow* pr = new PianorollWindow (string_compose (_("Pianoroll: %1"), _region->name()), track->session());
-
-	pr->set (track, midi_region());
-	pr->set_show_source (false);
-	pr->show_all ();
-	pr->present ();
-
-	pr->signal_delete_event().connect (sigc::mem_fun (*this, &MidiRegionView::pianoroll_window_deleted), false);
-	_editor = pr;
-}
-
 bool
 MidiRegionView::pianoroll_window_deleted (GdkEventAny*)
 {
@@ -728,7 +711,21 @@ MidiRegionView::pianoroll_window_deleted (GdkEventAny*)
 void
 MidiRegionView::show_region_editor ()
 {
-	edit_in_pianoroll_window ();
+	if (!_editor) {
+		std::shared_ptr<MidiTrack> track = std::dynamic_pointer_cast<MidiTrack> (trackview.stripable());
+		assert (track);
+
+		PianorollWindow* pr = new PianorollWindow (string_compose (_("Pianoroll: %1"), _region->name()), track->session());
+
+		pr->set (track, midi_region());
+		pr->set_show_source (false);
+
+		pr->signal_delete_event().connect (sigc::mem_fun (*this, &MidiRegionView::pianoroll_window_deleted), false);
+		_editor = pr;
+	}
+
+	_editor->show_all ();
+	_editor->present ();
 }
 
 void
diff --git a/gtk2_ardour/midi_region_view.h b/gtk2_ardour/midi_region_view.h
index eff7b57c64..efa968298c 100644
--- a/gtk2_ardour/midi_region_view.h
+++ b/gtk2_ardour/midi_region_view.h
@@ -134,7 +134,6 @@ public:
 	void set_visibility_note_range (MidiViewBackground::VisibleNoteRange, bool);
 
 	MergeableLine* make_merger ();
-	void edit_in_pianoroll_window ();
 	void show_region_editor ();
 	void hide_region_editor ();