diff --git a/tests/sys/netipsec/tunnel/empty.sh b/tests/sys/netipsec/tunnel/empty.sh
index dc1d3708f744..56480d21f4ec 100755
--- a/tests/sys/netipsec/tunnel/empty.sh
+++ b/tests/sys/netipsec/tunnel/empty.sh
@@ -1,43 +1,43 @@
 
 . $(atf_get_srcdir)/utils.subr
 
 atf_test_case "v4" "cleanup"
 v4_head()
 {
 	atf_set descr 'IPSec inet4 tunnel using NULL encryption'
 	atf_set require.user root
 }
 
 v4_body()
 {
 	# Can't use filename "null" for this script: PR 223564
-	ist_test 4 null ""
+	ist_test 4 null "1234"
 }
 
 v4_cleanup()
 {
 	ist_cleanup
 }
 
 atf_test_case "v6" "cleanup"
 v6_head()
 {
 	atf_set descr 'IPSec inet6 tunnel using NULL encryption'
 	atf_set require.user root
 }
 
 v6_body()
 {
-	ist_test 6 null ""
+	ist_test 6 null "5678"
 }
 
 v6_cleanup()
 {
 	ist_cleanup
 }
 
 atf_init_test_cases()
 {
 	atf_add_test_case "v4"
 	atf_add_test_case "v6"
 }