diff --git a/Voronoi_diagram_2/include/CGAL/Delaunay_triangulation_on_sphere_adaptation_traits_2.h b/Voronoi_diagram_2/include/CGAL/Delaunay_triangulation_on_sphere_adaptation_traits_2.h
new file mode 100644
index 00000000000..a2733336e5b
--- /dev/null
+++ b/Voronoi_diagram_2/include/CGAL/Delaunay_triangulation_on_sphere_adaptation_traits_2.h
@@ -0,0 +1,62 @@
+// Copyright (c) 2021 GeometryFactory
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org).
+//
+// $URL$
+// $Id$
+// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
+//
+//
+// Author(s)     : Mael Rouxel-Labbé
+
+#ifndef CGAL_DELAUNAY_TRIANGULATION_ADAPTATION_TRAITS_2_H
+#define CGAL_DELAUNAY_TRIANGULATION_ADAPTATION_TRAITS_2_H 1
+
+#include <CGAL/license/Voronoi_diagram_2.h>
+
+#include <CGAL/Voronoi_diagram_2/basic.h>
+#include <CGAL/Voronoi_diagram_2/Adaptation_traits_functors.h>
+#include <CGAL/Voronoi_diagram_2/Construct_dual_points.h>
+#include <CGAL/Voronoi_diagram_2/Site_accessors.h>
+
+namespace CGAL {
+
+template <typename DTOS>
+struct Delaunay_triangulation_on_sphere_adaptation_traits_2
+{
+public:
+  typedef DTOS                                                       Delaunay_graph;
+  typedef typename Delaunay_graph::Geom_traits                       Geom_traits;
+
+  typedef CGAL_VORONOI_DIAGRAM_2_INS::DToS2_Point_accessor<DTOS>     Access_site_2;
+  typedef CGAL_VORONOI_DIAGRAM_2_INS::DToS2_Voronoi_point_2<DTOS>    Construct_Voronoi_point_2;
+
+  typedef typename Delaunay_graph::Vertex_handle                     Delaunay_vertex_handle;
+  typedef typename Delaunay_graph::Edge                              Delaunay_edge;
+  typedef typename Delaunay_graph::Face_handle                       Delaunay_face_handle;
+
+  typedef CGAL::Tag_false                                            Has_nearest_site_2;
+  typedef CGAL_VORONOI_DIAGRAM_2_INS::Null_functor                   Nearest_site_2;
+
+  Delaunay_triangulation_on_sphere_adaptation_traits_2(const DTOS& dtos) : dtos(dtos) { }
+
+  Access_site_2 access_site_2_object() const
+  { return Access_site_2(dtos); }
+
+  Construct_Voronoi_point_2 construct_Voronoi_point_2_object() const
+  { return Construct_Voronoi_point_2(dtos); }
+
+  Nearest_site_2 nearest_site_2_object() const
+  { return Nearest_site_2(); }
+
+  typedef typename Geom_traits::Point_on_sphere_2                    Point_2;
+  typedef Point_2                                                    Site_2;
+
+private:
+  const DTOS& dtos;
+};
+
+} //namespace CGAL
+
+#endif // CGAL_DELAUNAY_TRIANGULATION_ADAPTATION_TRAITS_2_H
diff --git a/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Construct_dual_points.h b/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Construct_dual_points.h
index 993dacbeae9..af54b688b8d 100644
--- a/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Construct_dual_points.h
+++ b/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Construct_dual_points.h
@@ -77,6 +77,31 @@ public:
 
 //=========================================================================
 
+template<class DTOS>
+struct DToS2_Voronoi_point_2
+{
+private:
+  typedef typename DTOS::Geom_traits                       Geom_traits;
+  typedef typename Geom_traits::Point_on_sphere_2          Point_on_sphere_2;
+
+public:
+  typedef Point_on_sphere_2                                result_type;
+  typedef typename DTOS::Face_handle                       Face_handle;
+
+  DToS2_Voronoi_point_2(const DTOS& dtos) : dtos(dtos) { }
+
+  result_type operator()(const Face_handle f) const
+  {
+    return dtos.geom_traits().construct_circumcenter_on_sphere_2_object()(
+             dtos.point(f, 0), dtos.point(f, 1), dtos.point(f, 2));
+  }
+
+private:
+  const DTOS& dtos;
+};
+
+//=========================================================================
+
 template<class SVD2>
 class Segment_Voronoi_diagram_Voronoi_point_2
 {
diff --git a/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Site_accessors.h b/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Site_accessors.h
index 50f7a347f56..e1d45d99a15 100644
--- a/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Site_accessors.h
+++ b/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Site_accessors.h
@@ -15,12 +15,11 @@
 
 #include <CGAL/license/Voronoi_diagram_2.h>
 
-
 #include <CGAL/Voronoi_diagram_2/basic.h>
 
 namespace CGAL {
-
-namespace VoronoiDiagram_2 { namespace Internal {
+namespace VoronoiDiagram_2 {
+namespace Internal {
 
 //=========================================================================
 //=========================================================================
@@ -71,10 +70,32 @@ struct Point_accessor
 };
 
 //=========================================================================
+
+template <typename DTOS>
+struct DToS2_Point_accessor
+{
+private:
+  typedef typename DTOS::Geom_traits::Point_on_sphere_2      Point_on_sphere_2;
+
+public:
+  typedef const Point_on_sphere_2&                           result_type;
+  typedef typename DTOS::Vertex_handle                       Vertex_handle;
+
+  DToS2_Point_accessor(const DTOS& dtos) : dtos(dtos) { }
+
+  result_type operator()(const Vertex_handle v) const
+  {
+    return dtos.point(v);
+  }
+
+private:
+  const DTOS& dtos;
+};
+
 //=========================================================================
 
-} } //namespace VoronoiDiagram_2::Internal
-
-} //namespace CGAL
+} // namespace Internal
+} // namespace VoronoiDiagram_2
+} // namespace CGAL
 
 #endif // CGAL_VORONOI_DIAGRAM_2_SITE_ACCESSORS_H