diff --git a/gtk2_ardour/midi_region_view.cc b/gtk2_ardour/midi_region_view.cc
index 2170013f3f..3f3bd9c626 100644
--- a/gtk2_ardour/midi_region_view.cc
+++ b/gtk2_ardour/midi_region_view.cc
@@ -3912,7 +3912,7 @@ MidiRegionView::update_ghost_note (double x, double y, uint32_t state)
 	_ghost_note->show();
 
 	/* calculate time in of a single grid units worth of beats, at the start of source */
-	const Temporal::Beats length = get_grid_beats (_region->source_position()) + snapped_beats;
+	const Temporal::Beats length = get_grid_beats (_region->source_position() + timepos_t (snapped_beats));
 
 	_ghost_note->note()->set_time (snapped_beats);
 	_ghost_note->note()->set_length (length);