diff --git a/sbin/shutdown/shutdown.8 b/sbin/shutdown/shutdown.8
--- a/sbin/shutdown/shutdown.8
+++ b/sbin/shutdown/shutdown.8
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd November 7, 2022
+.Dd August 22, 2024
 .Dt SHUTDOWN 8
 .Os
 .Sh NAME
@@ -43,6 +43,7 @@
 .Fl o
 .Op Fl n
 .Oc
+.Op Fl W
 .Ar time
 .Op Ar warning-message ...
 .Nm poweroff
@@ -113,6 +114,11 @@
 or
 .Xr reboot 8 .
 This option should probably not be used.
+.It Fl W
+Suppress the warning message to all logged in users about system shutdown.
+It is an error to supply a
+.Ar warning-message
+when warnings are suppressed.
 .It Ar time
 .Ar Time
 is the time at which
diff --git a/sbin/shutdown/shutdown.c b/sbin/shutdown/shutdown.c
--- a/sbin/shutdown/shutdown.c
+++ b/sbin/shutdown/shutdown.c
@@ -43,6 +43,7 @@
 #include <pwd.h>
 #include <setjmp.h>
 #include <signal.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -86,7 +87,7 @@
 static void die_you_gravy_sucking_pig_dog(void);
 static void finish(int);
 static void getoffset(char *);
-static void loop(void);
+static void loop(bool);
 static void nolog(void);
 static void timeout(int);
 static void timewarn(int);
@@ -100,12 +101,14 @@
 	char *p, *endp;
 	struct passwd *pw;
 	int arglen, ch, len, readstdin;
+	bool dowarn;
 
 #ifndef DEBUG
 	if (geteuid())
 		errx(1, "NOT super-user");
 #endif
 
+	dowarn = true;
 	nosync = NULL;
 	readstdin = 0;
 
@@ -130,7 +133,7 @@
 		goto poweroff;
 	}
 
-	while ((ch = getopt(argc, argv, "-chknopr")) != -1)
+	while ((ch = getopt(argc, argv, "-chknoprW")) != -1)
 		switch (ch) {
 		case '-':
 			readstdin = 1;
@@ -156,6 +159,9 @@
 		case 'r':
 			doreboot = 1;
 			break;
+		case 'W':
+			dowarn = false;
+			break;
 		case '?':
 		default:
 			usage((char *)NULL);
@@ -178,6 +184,8 @@
 	getoffset(*argv++);
 
 poweroff:
+	if (!dowarn && *argv != NULL)
+		usage("warning-message supplied but suppressed with -W");
 	if (*argv) {
 		for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
 			arglen = strlen(*argv);
@@ -235,12 +243,12 @@
 	setsid();
 #endif
 	openlog("shutdown", LOG_CONS, LOG_AUTH);
-	loop();
+	loop(dowarn);
 	return(0);
 }
 
 static void
-loop(void)
+loop(bool dowarn)
 {
 	struct interval *tp;
 	u_int sltime;
@@ -263,13 +271,14 @@
 		 * the next wait time.
 		 */
 		if ((sltime = offset - tp->timeleft)) {
-			if (sltime > (u_int)(tp->timetowait / 5))
+			if (dowarn && sltime > (u_int)(tp->timetowait / 5))
 				timewarn(offset);
 			(void)sleep(sltime);
 		}
 	}
 	for (;; ++tp) {
-		timewarn(tp->timeleft);
+		if (dowarn)
+			timewarn(tp->timeleft);
 		if (!logged && tp->timeleft <= NOLOG_TIME) {
 			logged = 1;
 			nolog();
@@ -584,7 +593,7 @@
 	if (cp != NULL)
 		warnx("%s", cp);
 	(void)fprintf(stderr,
-	    "usage: shutdown [-] [-c | -h | -p | -r | -k] [-o [-n]] time [warning-message ...]\n"
+	    "usage: shutdown [-] [-c | -h | -p | -r | -k] [-o [-n]] -W time [warning-message ...]\n"
 	    "       poweroff\n");
 	exit(1);
 }