diff --git a/sbin/ipfw/main.c b/sbin/ipfw/main.c
index be6c093f303b..109b62b7de43 100644
--- a/sbin/ipfw/main.c
+++ b/sbin/ipfw/main.c
@@ -356,6 +356,7 @@ ipfw_main(int oldac, char **oldav)
 	 */
 	co.do_nat = 0;
 	co.do_pipe = 0;
+	co.use_set = 0;
 	if (!strncmp(*av, "nat", strlen(*av)))
  		co.do_nat = 1;
  	else if (!strncmp(*av, "pipe", strlen(*av)))