diff --git a/sys/dev/sound/pcm/dsp.c b/sys/dev/sound/pcm/dsp.c
index 81d75da9f446..2652d9afeae3 100644
--- a/sys/dev/sound/pcm/dsp.c
+++ b/sys/dev/sound/pcm/dsp.c
@@ -66,7 +66,7 @@ dsp_get_info(dev_t dev)
 	int unit;
 
 	unit = PCMUNIT(dev);
-	if (unit > devclass_get_maxunit(pcm_devclass))
+	if (unit >= devclass_get_maxunit(pcm_devclass))
 		return NULL;
 	d = devclass_get_softc(pcm_devclass, unit);
 
@@ -1024,7 +1024,7 @@ dsp_clone(void *arg, char *name, int namelen, dev_t *dev)
 
 	return;
 gotit:
-	if (unit == -1 || unit > devclass_get_maxunit(pcm_devclass))
+	if (unit == -1 || unit >= devclass_get_maxunit(pcm_devclass))
 		return;
 
 	cont = 1;
diff --git a/sys/dev/sound/pcm/sndstat.c b/sys/dev/sound/pcm/sndstat.c
index 25c71ed7f55b..a16c07e85c7a 100644
--- a/sys/dev/sound/pcm/sndstat.c
+++ b/sys/dev/sound/pcm/sndstat.c
@@ -140,7 +140,7 @@ sndstat_prepare(struct sbuf *s)
 	} else
 		sbuf_printf(s, "Installed devices:\n");
 
-    	for (i = 0; i <= devclass_get_maxunit(pcm_devclass); i++) {
+    	for (i = 0; i < devclass_get_maxunit(pcm_devclass); i++) {
 		d = devclass_get_softc(pcm_devclass, i);
 		if (!d)
 			continue;
diff --git a/sys/dev/sound/pcm/sound.c b/sys/dev/sound/pcm/sound.c
index 89cd4d02d297..baf90e0ba199 100644
--- a/sys/dev/sound/pcm/sound.c
+++ b/sys/dev/sound/pcm/sound.c
@@ -163,7 +163,7 @@ sysctl_hw_sndunit(SYSCTL_HANDLER_ARGS)
 	unit = snd_unit;
 	error = sysctl_handle_int(oidp, &unit, sizeof(unit), req);
 	if (error == 0 && req->newptr != NULL) {
-		if (unit < 0 || unit > devclass_get_maxunit(pcm_devclass))
+		if (unit < 0 || unit >= devclass_get_maxunit(pcm_devclass))
 			return EINVAL;
 		d = devclass_get_softc(pcm_devclass, unit);
 		if (d == NULL || SLIST_EMPTY(&d->channels))