diff --git a/Surface_mesher/include/CGAL/Implicit_surface_3.h b/Surface_mesher/include/CGAL/Implicit_surface_3.h
index ebad47e4311..404c972ac89 100644
--- a/Surface_mesher/include/CGAL/Implicit_surface_3.h
+++ b/Surface_mesher/include/CGAL/Implicit_surface_3.h
@@ -86,6 +86,11 @@ namespace CGAL {
         v1->point().element_index() != v3->point().element_index();
     }
 
+    const Function& function() const
+    {
+      return func;
+    }
+
   private:
     Function func;
     Sphere_3 sphere;