diff --git a/tests/sys/netgraph/Makefile b/tests/sys/netgraph/Makefile
index f397e66a22bc..5a5e2ba13081 100644
--- a/tests/sys/netgraph/Makefile
+++ b/tests/sys/netgraph/Makefile
@@ -1,25 +1,27 @@
 # $FreeBSD$
 
 PACKAGE=	tests
 
 TESTSDIR=	${TESTSBASE}/sys/netgraph
 BINDIR=		${TESTSDIR}
 
 TAP_TESTS_SH+=	ng_macfilter_test
 
+# Serialize tests since some share netgraph node names.
+TEST_METADATA+=	is_exclusive=true
 TEST_METADATA.ng_macfilter_test+=	required_user="root"
 TEST_METADATA.ng_macfilter_test+=	required_programs="perl"
 
 ATF_TESTS_C+=	basic		\
 		bridge		\
 		hub		\
 		vlan_rotate	\
 
 SRCS.basic=	basic.c util.c
 SRCS.bridge=	bridge.c util.c
 SRCS.hub=	hub.c util.c
 SRCS.vlan_rotate=vlan_rotate.c util.c
 
 LIBADD+=	netgraph
 
 .include <bsd.test.mk>