diff --git a/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h b/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h
index a20a6643f50..d222d741100 100644
--- a/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h
+++ b/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h
@@ -27,6 +27,7 @@
 #include <CGAL/Point_3.h>
 #include <CGAL/Vector_3.h>
 #include <CGAL/boost/graph/helpers.h>
+#include <CGAL/boost/graph/named_params_helper.h>
 
 #undef CGAL_NEF_DEBUG
 #define CGAL_NEF_DEBUG 29
diff --git a/Weights/include/CGAL/Weights/cotangent_weights.h b/Weights/include/CGAL/Weights/cotangent_weights.h
index dc070c5c493..7bd3f706a4b 100644
--- a/Weights/include/CGAL/Weights/cotangent_weights.h
+++ b/Weights/include/CGAL/Weights/cotangent_weights.h
@@ -17,6 +17,7 @@
 #include <CGAL/Weights/utils.h>
 
 #include <CGAL/boost/graph/helpers.h>
+#include <CGAL/boost/graph/named_params_helper.h>
 #include <CGAL/Kernel_traits.h>
 #include <CGAL/Point_2.h>
 #include <CGAL/Point_3.h>