diff --git a/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_3/internal/Periodic_3_regular_triangulation_filtered_traits_3.h b/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_3/internal/Periodic_3_regular_triangulation_filtered_traits_3.h
index 0d4a3b6768f..93a91c8777d 100644
--- a/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_3/internal/Periodic_3_regular_triangulation_filtered_traits_3.h
+++ b/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_3/internal/Periodic_3_regular_triangulation_filtered_traits_3.h
@@ -34,6 +34,7 @@ template <typename K_, typename Off_>
 class Periodic_3_regular_triangulation_filtered_traits_base_3
   : public Periodic_3_regular_triangulation_traits_base_3<K_, Off_>
 {
+public:
   typedef Periodic_3_regular_triangulation_traits_base_3<K_, Off_>  Base;
   typedef K_                                                        Kernel;