diff --git a/isisd/topology/spgrid.h b/isisd/topology/spgrid.h
index f96c00f..1c1ceea 100644
--- a/isisd/topology/spgrid.h
+++ b/isisd/topology/spgrid.h
@@ -33,7 +33,7 @@
 };
 
 int           gen_spgrid_topology (struct vty *vty, struct list *topology);
-int           spgrid_check_params (struct vty *vty, int argc, char **argv);
+int           spgrid_check_params (struct vty *vty, int argc, const char **argv);
 
 
 #endif /* _ZEBRA_ISIS_TOPOLOGY_SPGRID_H */