diff --git a/Arrangement_on_surface_2/include/CGAL/Arr_geometry_traits/Conic_x_monotone_arc_2.h b/Arrangement_on_surface_2/include/CGAL/Arr_geometry_traits/Conic_x_monotone_arc_2.h
index 761e38b1693..ec70376642b 100644
--- a/Arrangement_on_surface_2/include/CGAL/Arr_geometry_traits/Conic_x_monotone_arc_2.h
+++ b/Arrangement_on_surface_2/include/CGAL/Arr_geometry_traits/Conic_x_monotone_arc_2.h
@@ -202,7 +202,7 @@ public:
     // Invalid arc:
     if (dir_res == EQUAL) return;
 
-    this->_info = (Conic_arc_2::IS_VALID | DEGREE_1);
+    this->_info = (static_cast<int>(Conic_arc_2::IS_VALID) | static_cast<int>(DEGREE_1));
     if (dir_res == SMALLER)
       this->_info = (this->_info | IS_DIRECTED_RIGHT);