diff --git a/Straight_skeleton_2/include/CGAL/draw_straight_skeleton_2.h b/Straight_skeleton_2/include/CGAL/draw_straight_skeleton_2.h
index aae20d8288f..8facb91c4c4 100644
--- a/Straight_skeleton_2/include/CGAL/draw_straight_skeleton_2.h
+++ b/Straight_skeleton_2/include/CGAL/draw_straight_skeleton_2.h
@@ -76,8 +76,10 @@ protected:
   */
   void compute_edge(Halfedge_const_handle eh)
   {
-    add_segment(eh->opposite()->vertex()->point(),
-                eh->vertex()->point());
+    if(eh->is_bisector())
+      add_segment(eh->opposite()->vertex()->point(), eh->vertex()->point(), CGAL::red());
+    else
+      add_segment(eh->opposite()->vertex()->point(), eh->vertex()->point(), CGAL::black());
   }
   /*
   void compute_vertex(Vertex_const_handle vh)