Index: arp-scan.c
--- arp-scan.c.orig
+++ arp-scan.c
@@ -454,6 +454,11 @@ main(int argc, char *argv[]) {
          err_sys("open %s", pkt_filename);
    }
    /*
+    * Setup is done at this point, so it's a natural point to pledge().
+    */
+   if (pledge("stdio dns bpf", NULL) == -1)
+      err_sys("pledge");
+   /*
     * Create and initialise array of pointers to host entries.
     */
    helistptr = Malloc(num_hosts * sizeof(host_entry *));