diff --git a/Surface_mesh_parameterization/include/CGAL/Surface_mesh_parameterization/MVC_post_processor_3.h b/Surface_mesh_parameterization/include/CGAL/Surface_mesh_parameterization/MVC_post_processor_3.h
index de09347e762..0c0e9e336ca 100644
--- a/Surface_mesh_parameterization/include/CGAL/Surface_mesh_parameterization/MVC_post_processor_3.h
+++ b/Surface_mesh_parameterization/include/CGAL/Surface_mesh_parameterization/MVC_post_processor_3.h
@@ -642,7 +642,7 @@ private:
 
   /// Color the faces with inside/outside information and fix the border.
   template <typename CT, typename VertexParameterizedMap>
-  Error_code prepare_CT_for_parameterization(const CT& ct,
+  Error_code prepare_CT_for_parameterization(CT& ct,
                                              VertexParameterizedMap vpmap) const
   {
     Error_code status = OK;