diff --git a/Mesh_3/include/CGAL/Mesh_3/detect_triple_lines.h b/Mesh_3/include/CGAL/Mesh_3/detect_triple_lines.h
index b0c292d2e89..3eaf9c4d3ec 100644
--- a/Mesh_3/include/CGAL/Mesh_3/detect_triple_lines.h
+++ b/Mesh_3/include/CGAL/Mesh_3/detect_triple_lines.h
@@ -17,6 +17,8 @@
 #ifndef CGAL_MESH_3_DETECT_TRIPLE_LINES_H
 #define CGAL_MESH_3_DETECT_TRIPLE_LINES_H
 
+#include <CGAL/license/Mesh_3.h>
+
 #include <CGAL/Mesh_3/triple_lines_extraction/coordinates.h>
 #include <CGAL/Mesh_3/triple_lines_extraction/combinations.h>
 #include <CGAL/Mesh_3/triple_lines_extraction/cases_table.h>