diff --git a/tools/testing/selftests/net/arp_ndisc_untracked_subnets.sh b/tools/testing/selftests/net/arp_ndisc_untracked_subnets.sh
index c899b446acb6..327427ec10f5 100755
--- a/tools/testing/selftests/net/arp_ndisc_untracked_subnets.sh
+++ b/tools/testing/selftests/net/arp_ndisc_untracked_subnets.sh
@@ -150,7 +150,7 @@ arp_test_gratuitous() {
 	fi
 	# Supply arp_accept option to set up which sets it in sysctl
 	setup ${arp_accept}
-	ip netns exec ${HOST_NS} arping -A -U ${HOST_ADDR} -c1 2>&1 >/dev/null
+	ip netns exec ${HOST_NS} arping -A -I ${HOST_INTF} -U ${HOST_ADDR} -c1 2>&1 >/dev/null
 
 	if verify_arp $1 $2; then
 		printf "    TEST: %-60s  [ OK ]\n" "${test_msg[*]}"