diff --git a/gtk2_ardour/editor_ops.cc b/gtk2_ardour/editor_ops.cc
index 6c48fa4e4f..d749e23914 100644
--- a/gtk2_ardour/editor_ops.cc
+++ b/gtk2_ardour/editor_ops.cc
@@ -4775,7 +4775,7 @@ Editor::duplicate_some_regions (RegionSelection& regions, float times)
 
 	framepos_t const start_frame = regions.start ();
 	framepos_t const end_frame = regions.end_frame ();
-	framecnt_t const gap = end_frame - start_frame;
+	framecnt_t const gap = end_frame - start_frame + 1;
 
 	begin_reversible_command (Operations::duplicate_region);
 
@@ -4790,7 +4790,7 @@ Editor::duplicate_some_regions (RegionSelection& regions, float times)
 		latest_regionviews.clear ();
 		sigc::connection c = rtv->view()->RegionViewAdded.connect (sigc::mem_fun(*this, &Editor::collect_new_region_view));
 
-		framepos_t const position = end_frame + (r->first_frame() - start_frame);
+		framepos_t const position = end_frame + (r->first_frame() - start_frame + 1);
  		playlist = (*i)->region()->playlist();
 		playlist->clear_changes ();
 		playlist->duplicate (r, position, gap, times);
@@ -4841,7 +4841,7 @@ Editor::duplicate_selection (float times)
 		} else {
 			end = selection->time.end_frame();
 		}
-		playlist->duplicate (*ri, end, times);
+		playlist->duplicate (*ri, end + 1, times);
 
 		if (!in_command) {
 			begin_reversible_command (_("duplicate selection"));