diff --git a/sys/conf/majors b/sys/conf/majors
index ea6537eaf6f9..8b186d906ceb 100644
--- a/sys/conf/majors
+++ b/sys/conf/majors
@@ -165,7 +165,6 @@
 165	net		Network drivers <jlemon>
 166	ciss		Compaq SmartArray 5* adapter <msmith>
 167	ufm		USB Fm Radio
-168	sab		Siemens SAB82532 serial chip <jake>
 168	XXX		used by pst in RELENG_4
 170	pst		Promise SuperTrak (uses 168 in RELENG_4)
 171	mide		LSI MegaRAID IDE (control device)
@@ -179,7 +178,6 @@
 179	raid		RAIDframe (disk device)
 180	nvidia		NVIDIA (nvidiaN/nvidiactl) <mdodd>
 181	casm		HP/Compaq ProLiant Advanced Server Management <peter>
-182	zs		Zilog 8350 serial chip <jake>
 183	smapi		SMAPI BIOS interface <mdodd>
 200	??		entries from 200-252 are reserved for local use
 252	??		entries from 200-252 are reserved for local use
diff --git a/sys/dev/sab/sab.c b/sys/dev/sab/sab.c
index 9218beed4984..f77054f74e86 100644
--- a/sys/dev/sab/sab.c
+++ b/sys/dev/sab/sab.c
@@ -68,8 +68,6 @@
 
 #include <dev/sab/sab82532reg.h>
 
-#define	CDEV_MAJOR		168
-
 #define	SAB_READ(sc, r) \
 	bus_space_read_1((sc)->sc_bt, (sc)->sc_bh, (r))
 #define	SAB_WRITE(sc, r, v) \
@@ -171,7 +169,7 @@ static struct cdevsw sabtty_cdevsw = {
 	/* mmap */	nommap,
 	/* strategy */	nostrategy,
 	/* name */	"sabtty",
-	/* major */	CDEV_MAJOR,
+	/* major */	MAJOR_AUTO,
 	/* dump */	nodump,
 	/* psize */	nopsize,
 	/* flags */	D_TTY | D_KQFILTER,
diff --git a/sys/dev/zs/zs.c b/sys/dev/zs/zs.c
index 4f54b413822f..718652180d9b 100644
--- a/sys/dev/zs/zs.c
+++ b/sys/dev/zs/zs.c
@@ -99,8 +99,6 @@
 #include <dev/zs/z8530reg.h>
 #include <dev/zs/z8530var.h>
 
-#define	CDEV_MAJOR	182
-
 #define	ZS_READ(sc, r) \
 	bus_space_read_1((sc)->sc_bt, (r), 0)
 #define	ZS_WRITE(sc, r, v) \
@@ -161,7 +159,7 @@ static struct cdevsw zstty_cdevsw = {
 	/* mmap */	nommap,
 	/* strategy */	nostrategy,
 	/* name */	"zstty",
-	/* major */	CDEV_MAJOR,
+	/* major */	MAJOR_AUTO,
 	/* dump */	nodump,
 	/* psize */	nopsize,
 	/* flags */	D_TTY | D_KQFILTER,