diff --git a/sys/netinet/ip_carp.c b/sys/netinet/ip_carp.c
--- a/sys/netinet/ip_carp.c
+++ b/sys/netinet/ip_carp.c
@@ -2986,7 +2986,7 @@
 	MPASS(family_id != 0);
 
 	ret = genl_register_cmds(CARP_NL_FAMILY_NAME, carp_cmds,
-	    NL_ARRAY_LEN(carp_cmds));
+	    nitems(carp_cmds));
 	MPASS(ret);
 }
 
diff --git a/sys/netlink/netlink_ctl.h b/sys/netlink/netlink_ctl.h
--- a/sys/netlink/netlink_ctl.h
+++ b/sys/netlink/netlink_ctl.h
@@ -65,8 +65,6 @@
 		((char *)NLA_NEXT(_attr) <= (char *)_end);	\
 		_attr = (_len -= NLA_ALIGN(_attr->nla_len), NLA_NEXT(_attr)))
 
-#define	NL_ARRAY_LEN(_a)	(sizeof(_a) / sizeof((_a)[0]))
-
 #include <netlink/netlink_message_writer.h>
 #include <netlink/netlink_message_parser.h>
 
diff --git a/sys/netlink/netlink_generic.c b/sys/netlink/netlink_generic.c
--- a/sys/netlink/netlink_generic.c
+++ b/sys/netlink/netlink_generic.c
@@ -284,7 +284,7 @@
 {
 	NL_VERIFY_PARSERS(all_parsers);
 	ctrl_family_id = genl_register_family(CTRL_FAMILY_NAME, 0, 2, CTRL_ATTR_MAX);
-	genl_register_cmds(CTRL_FAMILY_NAME, nlctrl_cmds, NL_ARRAY_LEN(nlctrl_cmds));
+	genl_register_cmds(CTRL_FAMILY_NAME, nlctrl_cmds, nitems(nlctrl_cmds));
 	ctrl_group_id = genl_register_group(CTRL_FAMILY_NAME, "notify");
 	family_event_tag = EVENTHANDLER_REGISTER(genl_family_event, nlctrl_notify, NULL,
 	    EVENTHANDLER_PRI_ANY);
diff --git a/sys/netlink/netlink_message_parser.h b/sys/netlink/netlink_message_parser.h
--- a/sys/netlink/netlink_message_parser.h
+++ b/sys/netlink/netlink_message_parser.h
@@ -128,8 +128,8 @@
 	.nl_hdr_off = sizeof(_t),				\
 	.fp = &((_fp)[0]),					\
 	.np = &((_np)[0]),					\
-	.fp_size = NL_ARRAY_LEN(_fp),				\
-	.np_size = NL_ARRAY_LEN(_np),				\
+	.fp_size = nitems(_fp),					\
+	.np_size = nitems(_np),					\
 	.sp = _sp,						\
 	.post_parse = _pp,					\
 }
@@ -146,14 +146,14 @@
 	.out_hdr_off = sizeof(_o),			\
 	.fp = &((_fp)[0]),				\
 	.np = &((_np)[0]),				\
-	.fp_size = NL_ARRAY_LEN(_fp),			\
-	.np_size = NL_ARRAY_LEN(_np),			\
+	.fp_size = nitems(_fp),				\
+	.np_size = nitems(_np),				\
 }
 
 #define	NL_DECLARE_ATTR_PARSER_EXT(_name, _np, _pp)	\
 static const struct nlhdr_parser _name = {		\
 	.np = &((_np)[0]),				\
-	.np_size = NL_ARRAY_LEN(_np),			\
+	.np_size = nitems(_np),				\
 	.post_parse = (_pp)				\
 }
 
@@ -308,7 +308,7 @@
 #endif
 }
 void nl_verify_parsers(const struct nlhdr_parser **parser, int count);
-#define	NL_VERIFY_PARSERS(_p)	nl_verify_parsers((_p), NL_ARRAY_LEN(_p))
+#define	NL_VERIFY_PARSERS(_p)	nl_verify_parsers((_p), nitems(_p))
 
 static inline int
 nl_parse_nlmsg(struct nlmsghdr *hdr, const struct nlhdr_parser *parser,
diff --git a/sys/netlink/route/iface.c b/sys/netlink/route/iface.c
--- a/sys/netlink/route/iface.c
+++ b/sys/netlink/route/iface.c
@@ -1522,7 +1522,7 @@
 	    ifnet_link_event, rtnl_handle_iflink, NULL,
 	    EVENTHANDLER_PRI_ANY);
 	NL_VERIFY_PARSERS(all_parsers);
-	rtnl_register_messages(cmd_handlers, NL_ARRAY_LEN(cmd_handlers));
+	rtnl_register_messages(cmd_handlers, nitems(cmd_handlers));
 }
 
 void
diff --git a/sys/netlink/route/neigh.c b/sys/netlink/route/neigh.c
--- a/sys/netlink/route/neigh.c
+++ b/sys/netlink/route/neigh.c
@@ -589,7 +589,7 @@
 rtnl_neighs_init(void)
 {
 	NL_VERIFY_PARSERS(all_parsers);
-	rtnl_register_messages(cmd_handlers, NL_ARRAY_LEN(cmd_handlers));
+	rtnl_register_messages(cmd_handlers, nitems(cmd_handlers));
 	lle_event_p = EVENTHANDLER_REGISTER(lle_event, rtnl_lle_event, NULL,
 	    EVENTHANDLER_PRI_ANY);
 }
diff --git a/sys/netlink/route/nexthop.c b/sys/netlink/route/nexthop.c
--- a/sys/netlink/route/nexthop.c
+++ b/sys/netlink/route/nexthop.c
@@ -1119,5 +1119,5 @@
 rtnl_nexthops_init(void)
 {
 	NL_VERIFY_PARSERS(all_parsers);
-	rtnl_register_messages(cmd_handlers, NL_ARRAY_LEN(cmd_handlers));
+	rtnl_register_messages(cmd_handlers, nitems(cmd_handlers));
 }
diff --git a/sys/netlink/route/rt.c b/sys/netlink/route/rt.c
--- a/sys/netlink/route/rt.c
+++ b/sys/netlink/route/rt.c
@@ -1119,5 +1119,5 @@
 rtnl_routes_init(void)
 {
 	NL_VERIFY_PARSERS(all_parsers);
-	rtnl_register_messages(cmd_handlers, NL_ARRAY_LEN(cmd_handlers));
+	rtnl_register_messages(cmd_handlers, nitems(cmd_handlers));
 }
diff --git a/sys/netpfil/pf/pf_nl.c b/sys/netpfil/pf/pf_nl.c
--- a/sys/netpfil/pf/pf_nl.c
+++ b/sys/netpfil/pf/pf_nl.c
@@ -1985,7 +1985,7 @@
 	NL_VERIFY_PARSERS(all_parsers);
 
 	family_id = genl_register_family(PFNL_FAMILY_NAME, 0, 2, PFNL_CMD_MAX);
-	genl_register_cmds(PFNL_FAMILY_NAME, pf_cmds, NL_ARRAY_LEN(pf_cmds));
+	genl_register_cmds(PFNL_FAMILY_NAME, pf_cmds, nitems(pf_cmds));
 }
 
 void
diff --git a/sys/netpfil/pf/pflow.c b/sys/netpfil/pf/pflow.c
--- a/sys/netpfil/pf/pflow.c
+++ b/sys/netpfil/pf/pflow.c
@@ -1786,7 +1786,8 @@
 
 	family_id = genl_register_family(PFLOWNL_FAMILY_NAME, 0, 2, PFLOWNL_CMD_MAX);
 	MPASS(family_id != 0);
-	ret = genl_register_cmds(PFLOWNL_FAMILY_NAME, pflow_cmds, NL_ARRAY_LEN(pflow_cmds));
+	ret = genl_register_cmds(PFLOWNL_FAMILY_NAME, pflow_cmds,
+	    nitems(pflow_cmds));
 
 	return (ret ? 0 : ENODEV);
 }
diff --git a/sys/tests/ktest.c b/sys/tests/ktest.c
--- a/sys/tests/ktest.c
+++ b/sys/tests/ktest.c
@@ -370,7 +370,8 @@
 	family_id = genl_register_family(KTEST_FAMILY_NAME, 0, 1, KTEST_CMD_MAX);
 	MPASS(family_id != 0);
 
-	ret = genl_register_cmds(KTEST_FAMILY_NAME, ktest_cmds, NL_ARRAY_LEN(ktest_cmds));
+	ret = genl_register_cmds(KTEST_FAMILY_NAME, ktest_cmds,
+	    nitems(ktest_cmds));
 	MPASS(ret);
 }