diff --git a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp
index d30f413526a..87da9c75ca3 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp
@@ -73,8 +73,8 @@ void Scene_polyhedron_selection_item::initialize_buffers(Viewer_interface *viewe
     std::vector<float>(normals).swap(normals);
 
     nb_lines = positions_lines.size();
-   // positions_lines.resize(0);
-   // std::vector<float>(positions_lines).swap(positions_lines);
+    positions_lines.resize(0);
+    std::vector<float>(positions_lines).swap(positions_lines);
 
     nb_points = positions_points.size();
     positions_points.resize(0);