diff --git a/Surface_mesh_segmentation/include/CGAL/internal/auxiliary/graph.h b/Surface_mesh_segmentation/include/CGAL/internal/auxiliary/graph.h
index b84f5a0500d..8579a791c3e 100644
--- a/Surface_mesh_segmentation/include/CGAL/internal/auxiliary/graph.h
+++ b/Surface_mesh_segmentation/include/CGAL/internal/auxiliary/graph.h
@@ -242,6 +242,16 @@ void main()
 #ifndef __MAXFLOW_BLOCK_H__
 #define __MAXFLOW_BLOCK_H__
 
+#  if defined(CGAL_LICENSE_WARNING)
+     CGAL_pragma_warning("\nYou use the MaxFlow package of Vladimir Kolmogorov under the terms of the GPLv2+.")
+#  endif // CGAL_LICENSE_WARNING
+
+#  ifdef CGAL_LICENSE_ERROR
+#    error "You use the the MaxFlow package of Vladimir Kolmogorov under the terms of the GPLv2+.\
+You get this error, as you defined CGAL_LICENSE_ERROR."
+#  endif // CGAL_LICENSE_ERROR
+
+
 #include <stdlib.h>
 
 /***********************************************************************/