diff --git a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_meta_traits.h b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_meta_traits.h
index f3b04a1eea1..79fa2b45b13 100644
--- a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_meta_traits.h
+++ b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_meta_traits.h
@@ -130,6 +130,7 @@ class Gps_agg_meta_traits :
   typedef typename Base::Point_2                  Point_2;
   typedef typename Traits::Has_left_category      Has_left_category;
   typedef typename Traits::Has_boundary_category  Has_boundary_category;
+  typedef typename Traits::Boundary_category      Boundary_category;
   typedef typename Traits::Has_merge_category     Has_merge_category;
 
   typedef typename Base::Curve_data               Curve_data;
diff --git a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_traits_decorator.h b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_traits_decorator.h
index e5d1396d3ac..f2ca0ab385c 100644
--- a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_traits_decorator.h
+++ b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_traits_decorator.h
@@ -48,6 +48,7 @@ public:
   typedef typename Base::Compare_endpoints_xy_2    Base_Compare_endpoints_xy_2;
   typedef typename Base::Construct_opposite_2      Base_Construct_opposite_2;
   typedef typename Base::Has_boundary_category     Has_boundary_category;
+  typedef typename Base::Boundary_category         Boundary_category;
   typedef typename Base::Has_left_category         Has_left_category;
   typedef typename Base::Has_merge_category        Has_merge_category;