diff --git a/tests/sys/kern/Makefile b/tests/sys/kern/Makefile
--- a/tests/sys/kern/Makefile
+++ b/tests/sys/kern/Makefile
@@ -38,6 +38,7 @@
 ATF_TESTS_C+=	sys_getrandom
 ATF_TESTS_C+=	unix_dgram
 ATF_TESTS_C+=	unix_passfd_test
+TEST_METADATA.unix_passfd_test+=	is_exclusive="true"
 ATF_TESTS_C+=	unix_seqpacket_test
 TEST_METADATA.unix_seqpacket_test+=	timeout="15"
 ATF_TESTS_C+=	unix_socketpair_test