diff --git a/Arrangement_on_surface_2/include/CGAL/Arr_curve_data_traits_2.h b/Arrangement_on_surface_2/include/CGAL/Arr_curve_data_traits_2.h
index a9b55b05e8a..9d0b1dd9647 100644
--- a/Arrangement_on_surface_2/include/CGAL/Arr_curve_data_traits_2.h
+++ b/Arrangement_on_surface_2/include/CGAL/Arr_curve_data_traits_2.h
@@ -25,6 +25,7 @@
  * Definition of the Arr_curve_data_traits_2<> class template.
  */
 
+#include<CGAL/Arr_tags.h>
 #include<CGAL/Arr_geometry_traits/Curve_data_aux.h>
 #include<list>