diff --git a/Polygon_mesh_processing/include/CGAL/Polyhedral_envelope.h b/Polygon_mesh_processing/include/CGAL/Polyhedral_envelope.h
index a9b15aa24db..74dc79a975b 100644
--- a/Polygon_mesh_processing/include/CGAL/Polyhedral_envelope.h
+++ b/Polygon_mesh_processing/include/CGAL/Polyhedral_envelope.h
@@ -5,7 +5,7 @@
 //
 // $URL$
 // $Id$
-// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
+// SPDX-License-Identifier: ( GPL-3.0-or-later OR LicenseRef-Commercial ) AND MIT
 //
 // Author(s)     : Andreas Fabri
 //