diff --git a/sys/dev/speaker/spkr.c b/dev/speaker/spkr.c
--- a/sys/dev/speaker/spkr.c
+++ b/dev/speaker/spkr.c
@@ -14,9 +14,12 @@
 #include <sys/conf.h>
 #include <sys/ctype.h>
 #include <sys/malloc.h>
+#include <sys/mutex.h>
 #include <machine/clock.h>
 #include <dev/speaker/speaker.h>
 
+static	struct	mtx spkr_mtx;
+
 static	d_open_t	spkropen;
 static	d_close_t	spkrclose;
 static	d_write_t	spkrwrite;
@@ -24,7 +27,6 @@
 
 static struct cdevsw spkr_cdevsw = {
 	.d_version =	D_VERSION,
-	.d_flags =	D_NEEDGIANT,
 	.d_open =	spkropen,
 	.d_close =	spkrclose,
 	.d_write =	spkrwrite,
@@ -396,7 +398,6 @@
  * endtone(), and rest() functions defined above.
  */
 
-static int spkr_active = FALSE; /* exclusion flag */
 static char *spkr_inbuf;  /* incoming buf */
 
 static int
@@ -406,17 +407,17 @@
 	(void) printf("spkropen: entering with dev = %s\n", devtoname(dev));
 #endif /* DEBUG */
 
-	if (spkr_active)
+	int r;
+
+	r = mtx_trylock(&spkr_mtx);
+	if (r == 0)
 		return(EBUSY);
-	else {
 #ifdef DEBUG
-		(void) printf("spkropen: about to perform play initialization\n");
+	(void) printf("spkropen: about to perform play initialization\n");
 #endif /* DEBUG */
-		playinit();
-		spkr_inbuf = malloc(DEV_BSIZE, M_SPKR, M_WAITOK);
-		spkr_active = TRUE;
-		return(0);
-    	}
+	playinit();
+	spkr_inbuf = malloc(DEV_BSIZE, M_SPKR, M_WAITOK);
+	return(0);
 }
 
 static int
@@ -455,7 +456,7 @@
 	wakeup(&endtone);
 	wakeup(&endrest);
 	free(spkr_inbuf, M_SPKR);
-	spkr_active = FALSE;
+	mtx_unlock(&spkr_mtx);
 	return(0);
 }
 
@@ -511,12 +512,16 @@
 
 	switch(type) {
 	case MOD_LOAD: 
+		mtx_init(&spkr_mtx, "speaker lock", NULL, MTX_DEF);
 		speaker_dev = make_dev(&spkr_cdevsw, 0,
 		    UID_ROOT, GID_WHEEL, 0600, "speaker");
 		break;
 	case MOD_SHUTDOWN:
 	case MOD_UNLOAD:
 		destroy_dev(speaker_dev);
+		mtx_lock(&spkr_mtx);
+		mtx_unlock(&spkr_mtx);
+		mtx_destroy(&spkr_mtx);
 		break;
 	default:
 		error = EOPNOTSUPP;