diff --git a/Constrained_triangulation_3/include/CGAL/Constrained_Delaunay_triangulation_cell_base_3.h b/Constrained_triangulation_3/include/CGAL/Constrained_Delaunay_triangulation_cell_base_3.h
index 6578a61940f..97cc7cfb9e0 100644
--- a/Constrained_triangulation_3/include/CGAL/Constrained_Delaunay_triangulation_cell_base_3.h
+++ b/Constrained_triangulation_3/include/CGAL/Constrained_Delaunay_triangulation_cell_base_3.h
@@ -12,6 +12,8 @@
 #ifndef CGAL_CONSTRAINED_DELAUNAY_TRIANGULATION_CELL_BASE_3_H
 #define CGAL_CONSTRAINED_DELAUNAY_TRIANGULATION_CELL_BASE_3_H
 
+#include <CGAL/license/Constrained_triangulation_3.h>
+
 #include <CGAL/Constrained_Delaunay_triangulation_cell_data_3.h>
 #include <CGAL/Triangulation_cell_base_3.h>
 
diff --git a/Constrained_triangulation_3/include/CGAL/Constrained_Delaunay_triangulation_vertex_base_3.h b/Constrained_triangulation_3/include/CGAL/Constrained_Delaunay_triangulation_vertex_base_3.h
index b3c58fe7cdd..d21b2405cd6 100644
--- a/Constrained_triangulation_3/include/CGAL/Constrained_Delaunay_triangulation_vertex_base_3.h
+++ b/Constrained_triangulation_3/include/CGAL/Constrained_Delaunay_triangulation_vertex_base_3.h
@@ -13,6 +13,8 @@
 #ifndef CGAL_CONSTRAINED_DELAUNAY_TRIANGULATION_VERTEX_BASE_3_H
 #define CGAL_CONSTRAINED_DELAUNAY_TRIANGULATION_VERTEX_BASE_3_H
 
+#include <CGAL/license/Constrained_triangulation_3.h>
+
 #include <CGAL/Triangulation_vertex_base_3.h>
 #include <CGAL/Constrained_Delaunay_triangulation_vertex_data_3.h>
 #include <CGAL/SMDS_3/io_signature.h>
diff --git a/Constrained_triangulation_3/include/CGAL/Constrained_triangulation_3/internal/cdt_debug_io.h b/Constrained_triangulation_3/include/CGAL/Constrained_triangulation_3/internal/cdt_debug_io.h
index 785d1b880f4..95840160ef8 100644
--- a/Constrained_triangulation_3/include/CGAL/Constrained_triangulation_3/internal/cdt_debug_io.h
+++ b/Constrained_triangulation_3/include/CGAL/Constrained_triangulation_3/internal/cdt_debug_io.h
@@ -12,13 +12,16 @@
 #ifndef CGAL_CDT_3_DEBUG_IO_H
 #define CGAL_CDT_3_DEBUG_IO_H
 
-#include <ostream>
+#include <CGAL/license/Constrained_triangulation_3.h>
+
 #include <CGAL/boost/graph/IO/OFF.h>
 #include <CGAL/Surface_mesh.h>
 #include <CGAL/Polygon_mesh_processing/orient_polygon_soup.h>
 #include <CGAL/Polygon_mesh_processing/repair_polygon_soup.h>
 #include <CGAL/Polygon_mesh_processing/polygon_soup_to_polygon_mesh.h>
 
+#include <ostream>
+
 namespace CGAL {
 
   template <typename Tr, typename Facets>