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
@@ -7,6 +7,8 @@ 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"