diff --git a/lib/libmixer/Makefile b/lib/libmixer/Makefile
--- a/lib/libmixer/Makefile
+++ b/lib/libmixer/Makefile
@@ -19,8 +19,8 @@
 MLINKS+=	mixer.3 mixer_set_vol.3
 MLINKS+=	mixer.3 mixer_set_mute.3
 MLINKS+=	mixer.3 mixer_mod_recsrc.3
-MLINKS+=	mixer.3 mixer_get_dunit.3
-MLINKS+=	mixer.3 mixer_set_dunit.3
+MLINKS+=	mixer.3 mixer_get_default_unit.3
+MLINKS+=	mixer.3 mixer_set_default_unit.3
 MLINKS+=	mixer.3 mixer_get_mode.3
 MLINKS+=	mixer.3 mixer_get_nmixers.3
 MLINKS+=	mixer.3 MIX_ISDEV.3
diff --git a/lib/libmixer/Symbol.map b/lib/libmixer/Symbol.map
--- a/lib/libmixer/Symbol.map
+++ b/lib/libmixer/Symbol.map
@@ -15,8 +15,8 @@
 	mixer_set_vol;
 	mixer_set_mute;
 	mixer_mod_recsrc;
-	mixer_get_dunit;
-	mixer_set_dunit;
+	mixer_get_default_unit;
+	mixer_set_default_unit;
 	mixer_get_mode;
 	mixer_get_nmixers;
 };
diff --git a/lib/libmixer/mixer.h b/lib/libmixer/mixer.h
--- a/lib/libmixer/mixer.h
+++ b/lib/libmixer/mixer.h
@@ -113,8 +113,8 @@
 int mixer_set_vol(struct mixer *, mix_volume_t);
 int mixer_set_mute(struct mixer *, int);
 int mixer_mod_recsrc(struct mixer *, int);
-int mixer_get_dunit(void);
-int mixer_set_dunit(struct mixer *, int);
+int mixer_get_default_unit(void);
+int mixer_set_default_unit(struct mixer *, int);
 int mixer_get_mode(int);
 int mixer_get_nmixers(void);
 
diff --git a/lib/libmixer/mixer.3 b/lib/libmixer/mixer.3
--- a/lib/libmixer/mixer.3
+++ b/lib/libmixer/mixer.3
@@ -38,8 +38,8 @@
 .Nm mixer_set_vol ,
 .Nm mixer_set_mute ,
 .Nm mixer_mod_recsrc ,
-.Nm mixer_get_dunit ,
-.Nm mixer_set_dunit ,
+.Nm mixer_get_default_unit ,
+.Nm mixer_set_default_unit ,
 .Nm mixer_get_mode,
 .Nm mixer_get_nmixers ,
 .Nm MIX_ISDEV ,
@@ -80,9 +80,9 @@
 .Ft int
 .Fn mixer_mod_recsrc "struct mixer *m" "int opt"
 .Ft int
-.Fn mixer_get_dunit "void"
+.Fn mixer_get_default_unit "void"
 .Ft int
-.Fn mixer_set_dunit "struct mixer *m" "int unit"
+.Fn mixer_set_default_unit "struct mixer *m" "int unit"
 .Ft int
 .Fn mixer_get_mode "int unit"
 .Ft int
@@ -358,9 +358,9 @@
 .El
 .Pp
 The
-.Fn mixer_get_dunit
+.Fn mixer_get_default_unit
 and
-.Fn mixer_set_dunit
+.Fn mixer_set_default_unit
 functions get and set the default audio card in the system. Although this is
 not really a mixer feature, it's useful to have instead of having to use
 the
@@ -457,7 +457,7 @@
 .Fn mixer_set_mute ,
 .Fn mixer_mod_recsrc ,
 .Fn mixer_get_dunut ,
-.Fn mixer_set_dunit
+.Fn mixer_set_default_unit
 and
 .Fn mixer_get_nmixers
 functions return 0 or positive values on success and -1 on failure.
diff --git a/lib/libmixer/mixer.c b/lib/libmixer/mixer.c
--- a/lib/libmixer/mixer.c
+++ b/lib/libmixer/mixer.c
@@ -81,13 +81,13 @@
 		} else {
 			/* `name` is "/dev/mixer" so, we'll use the default unit. */
 			if (strncmp(name, BASEPATH, strlen(name)) == 0)
-				goto dunit;
+				goto default_unit;
 			m->unit = strtol(name + strlen(BASEPATH), NULL, 10);
 		}
 		(void)strlcpy(m->name, name, sizeof(m->name));
 	} else {
-dunit:
-		if ((m->unit = mixer_get_dunit()) < 0)
+default_unit:
+		if ((m->unit = mixer_get_default_unit()) < 0)
 			goto fail;
 		(void)snprintf(m->name, sizeof(m->name), "/dev/mixer%d", m->unit);
 	}
@@ -96,7 +96,7 @@
 		goto fail;
 
 	m->devmask = m->recmask = m->recsrc = 0;
-	m->f_default = m->unit == mixer_get_dunit();
+	m->f_default = m->unit == mixer_get_default_unit();
 	m->mode = mixer_get_mode(m->unit);
 	/* The unit number _must_ be set before the ioctl. */
 	m->mi.dev = m->unit;
@@ -420,7 +420,7 @@
  * and set the mixer structure's `f_default` flag.
  */
 int
-mixer_get_dunit(void)
+mixer_get_default_unit(void)
 {
 	size_t size;
 	int unit;
@@ -440,7 +440,7 @@
  * @param unit		the audio card number (e.g pcm0, pcm1, ...).
  */
 int
-mixer_set_dunit(struct mixer *m, int unit)
+mixer_set_default_unit(struct mixer *m, int unit)
 {
 	size_t size;
 
diff --git a/usr.sbin/mixer/mixer.c b/usr.sbin/mixer/mixer.c
--- a/usr.sbin/mixer/mixer.c
+++ b/usr.sbin/mixer/mixer.c
@@ -38,7 +38,7 @@
 static void printdev(struct mixer *, int);
 static void printrecsrc(struct mixer *, int); /* XXX: change name */
 /* Control handlers */
-static int mod_dunit(struct mix_dev *, void *);
+static int mod_default_unit(struct mix_dev *, void *);
 static int mod_volume(struct mix_dev *, void *);
 static int mod_mute(struct mix_dev *, void *);
 static int mod_recsrc(struct mix_dev *, void *);
@@ -46,11 +46,11 @@
 static int print_mute(struct mix_dev *, void *);
 static int print_recsrc(struct mix_dev *, void *);
 
-static const mix_ctl_t ctl_dunit = {
+static const mix_ctl_t ctl_default_unit = {
 	.parent_dev	= NULL,
 	.id		= -1,
 	.name		= "default_unit",
-	.mod		= mod_dunit,
+	.mod		= mod_default_unit,
 	.print		= NULL
 };
 
@@ -61,7 +61,7 @@
 	mix_ctl_t *cp;
 	char *name = NULL, buf[NAME_MAX];
 	char *p, *bufp, *devstr, *ctlstr, *valstr = NULL;
-	int dunit, i, n, pall = 1;
+	int du, i, n, pall = 1;
 	int aflag = 0, dflag = 0, oflag = 0, sflag = 0;
 	int ch;
 
@@ -71,7 +71,7 @@
 			aflag = 1;
 			break;
 		case 'd':
-			dunit = strtol(optarg, NULL, 10);
+			du = strtol(optarg, NULL, 10);
 			if (errno == EINVAL || errno == ERANGE)
 				err(1, "strtol");
 			dflag = 1;
@@ -119,7 +119,7 @@
 
 	initctls(m);
 
-	if (dflag && ctl_dunit.mod(m->dev, &dunit) < 0)
+	if (dflag && ctl_default_unit.mod(m->dev, &du) < 0)
 		goto parse;
 	if (sflag) {
 		printrecsrc(m, oflag);
@@ -287,20 +287,20 @@
 }
 
 static int
-mod_dunit(struct mix_dev *d, void *p)
+mod_default_unit(struct mix_dev *d, void *p)
 {
-	int dunit = *((int *)p);
+	int du = *((int *)p);
 	int n;
 
-	if ((n = mixer_get_dunit()) < 0) {
+	if ((n = mixer_get_default_unit()) < 0) {
 		warn("cannot get default unit");
 		return (-1);
 	}
-	if (mixer_set_dunit(d->parent_mixer, dunit) < 0) {
-		warn("cannot set default unit to: %d", dunit);
+	if (mixer_set_default_unit(d->parent_mixer, du) < 0) {
+		warn("cannot set default unit to: %d", du);
 		return (-1);
 	}
-	printf("%s: %d -> %d\n", ctl_dunit.name, n, dunit);
+	printf("%s: %d -> %d\n", ctl_default_unit.name, n, du);
 
 	return (0);
 }