diff --git a/usr.sbin/acpi/acpidump/acpi.c b/usr.sbin/acpi/acpidump/acpi.c
index fee5f5331780..4eae4548bab8 100644
--- a/usr.sbin/acpi/acpidump/acpi.c
+++ b/usr.sbin/acpi/acpidump/acpi.c
@@ -733,7 +733,7 @@ write_dsdt(int fd, struct ACPIsdt *rsdt, struct ACPIsdt *dsdt)
 		sdt.check = 0;
 		sum = acpi_checksum(dsdt->body, dsdt->len - SIZEOF_SDT_HDR);
 		ssdt = sdt_from_rsdt(rsdt, "SSDT", NULL);
-		while (sflag && ssdt != NULL) {
+		while (ssdt != NULL) {
 			sdt.len += ssdt->len - SIZEOF_SDT_HDR;
 			sum += acpi_checksum(ssdt->body,
 			    ssdt->len - SIZEOF_SDT_HDR);
@@ -748,7 +748,7 @@ write_dsdt(int fd, struct ACPIsdt *rsdt, struct ACPIsdt *dsdt)
 	write(fd, dsdt->body, dsdt->len - SIZEOF_SDT_HDR);
 
 	/* Write out any SSDTs (if present and the user requested this.) */
-	if (sflag && rsdt != NULL) {
+	if (rsdt != NULL) {
 		ssdt = sdt_from_rsdt(rsdt, "SSDT", NULL);
 		while (ssdt != NULL) {
 			write(fd, ssdt->body, ssdt->len - SIZEOF_SDT_HDR);
diff --git a/usr.sbin/acpi/acpidump/acpidump.8 b/usr.sbin/acpi/acpidump/acpidump.8
index 317148c448d2..b876a9d40ac9 100644
--- a/usr.sbin/acpi/acpidump/acpidump.8
+++ b/usr.sbin/acpi/acpidump/acpidump.8
@@ -38,7 +38,6 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl d
-.Op Fl s
 .Op Fl t
 .Op Fl h
 .Op Fl v
@@ -67,11 +66,9 @@ The
 .Nm
 utility can extract the DSDT data block from physical memory and store it into
 an output file and optionally also disassemble it.
-If Secondary System Description Table
+If any Secondary System Description Table
 (SSDT)
-entries exist, specifying the
-.Fl s
-option will include those tables in the output file and disassembly.
+entries exist, they will also be included in the output file and disassembly.
 .Pp
 When
 .Nm
@@ -128,9 +125,6 @@ The following options are supported by
 Disassemble the DSDT into ASL using
 .Xr iasl 8
 and print the results to stdout.
-.It Fl s
-Dump any SSDTs by concatenating them with the DSDT.
-The SSDTs are optional tables with the same format as the DSDT.
 .It Fl t
 Dump the contents of the various fixed tables listed above.
 .It Fl h
@@ -162,11 +156,6 @@ Verbose messages are enabled.
 .Sh BUGS
 The current implementation does not dump the BOOT structure or
 other miscellaneous tables.
-.Pp
-There is currently no way to override SSDTs so dumping them only provides
-information.
-Overriding the DSDT with a custom version that also includes the contents of
-SSDTs will result in multiple-definition errors.
 .Sh FILES
 .Bl -tag -width /dev/mem
 .It Pa /dev/mem
diff --git a/usr.sbin/acpi/acpidump/acpidump.c b/usr.sbin/acpi/acpidump/acpidump.c
index 0ebb5d02ed19..33610386456b 100644
--- a/usr.sbin/acpi/acpidump/acpidump.c
+++ b/usr.sbin/acpi/acpidump/acpidump.c
@@ -37,7 +37,6 @@
 #include "acpidump.h"
 
 int	dflag;	/* Disassemble AML using iasl(8) */
-int	sflag;	/* Include secondary (SSDT) tables. */
 int	tflag;	/* Dump contents of SDT tables */
 int	vflag;	/* Use verbose messages */
 
@@ -45,7 +44,7 @@ static void
 usage(const char *progname)
 {
 
-	fprintf(stderr, "usage: %s [-d] [-s] [-t] [-h] [-v] [-f dsdt_input] "
+	fprintf(stderr, "usage: %s [-d] [-t] [-h] [-v] [-f dsdt_input] "
 			"[-o dsdt_output]\n", progname);
 	exit(1);
 }
@@ -63,14 +62,11 @@ main(int argc, char *argv[])
 	if (argc < 2)
 		usage(progname);
 
-	while ((c = getopt(argc, argv, "dhstvf:o:")) != -1) {
+	while ((c = getopt(argc, argv, "dhtvf:o:")) != -1) {
 		switch (c) {
 		case 'd':
 			dflag = 1;
 			break;
-		case 's':
-			sflag = 1;
-			break;
 		case 't':
 			tflag = 1;
 			break;
diff --git a/usr.sbin/acpi/acpidump/acpidump.h b/usr.sbin/acpi/acpidump/acpidump.h
index b6f0a6300d04..ca56398af2a9 100644
--- a/usr.sbin/acpi/acpidump/acpidump.h
+++ b/usr.sbin/acpi/acpidump/acpidump.h
@@ -332,7 +332,6 @@ int		 acpi_checksum(void *, size_t);
 
 /* Command line flags */
 extern int	dflag;
-extern int	sflag;
 extern int	tflag;
 extern int	vflag;