diff --git a/gtk2_ardour/pianoroll_window.cc b/gtk2_ardour/pianoroll_window.cc
index cbf81ab78b..45ee60ecbb 100644
--- a/gtk2_ardour/pianoroll_window.cc
+++ b/gtk2_ardour/pianoroll_window.cc
@@ -32,6 +32,7 @@ using namespace ARDOUR;
 PianorollWindow::PianorollWindow (std::string const & name, Session& s)
 	: ArdourWindow (string_compose ("%1 - %2", PROGRAM_NAME, name))
 	, pianoroll (new Pianoroll (name))
+	, region_editor (nullptr)
 {
 	pianoroll->set_session (&s);
 	pianoroll->viewport().set_size_request (600, 120);
@@ -43,6 +44,7 @@ PianorollWindow::PianorollWindow (std::string const & name, Session& s)
 PianorollWindow::~PianorollWindow ()
 {
 	delete pianoroll;
+	delete region_editor;
 }
 
 void
@@ -51,6 +53,7 @@ PianorollWindow::set (std::shared_ptr<MidiTrack> track, std::shared_ptr<MidiRegi
 	pianoroll->set_track (track);
 	pianoroll->set_region (region);
 
+	delete region_editor;
 	region_editor = new RegionEditor (pianoroll->session(), region);
 	hpacker.pack_start (*region_editor, false, false);
 	hpacker.pack_start (pianoroll->contents(), true, true);