diff --git a/usr.sbin/acpi/acpidump/acpi.c b/usr.sbin/acpi/acpidump/acpi.c
--- a/usr.sbin/acpi/acpidump/acpi.c
+++ b/usr.sbin/acpi/acpidump/acpi.c
@@ -2643,6 +2643,22 @@
 		perror("rmdir");
 }
 
+void
+aml_disassemble_separate(ACPI_TABLE_HEADER *rsdt, ACPI_TABLE_HEADER *dsdp)
+{
+	ACPI_TABLE_HEADER *ssdt = NULL;
+
+	aml_disassemble(NULL, dsdp);
+	if (rsdt != NULL) {
+		for (;;) {
+			ssdt = sdt_from_rsdt(rsdt, "SSDT", ssdt);
+			if (ssdt == NULL)
+				break;
+			aml_disassemble(NULL, ssdt);
+		}
+	}
+}
+
 void
 sdt_print_all(ACPI_TABLE_HEADER *rsdp)
 {
diff --git a/usr.sbin/acpi/acpidump/acpidump.h b/usr.sbin/acpi/acpidump/acpidump.h
--- a/usr.sbin/acpi/acpidump/acpidump.h
+++ b/usr.sbin/acpi/acpidump/acpidump.h
@@ -144,6 +144,7 @@
 
 /* Disassemble the AML in the DSDT */
 void	 aml_disassemble(ACPI_TABLE_HEADER *, ACPI_TABLE_HEADER *);
+void	 aml_disassemble_separate(ACPI_TABLE_HEADER *, ACPI_TABLE_HEADER *);
 
 /* Routines for accessing tables in physical memory */
 ACPI_TABLE_RSDP *acpi_find_rsd_ptr(void);
diff --git a/usr.sbin/acpi/acpidump/acpidump.8 b/usr.sbin/acpi/acpidump/acpidump.8
--- a/usr.sbin/acpi/acpidump/acpidump.8
+++ b/usr.sbin/acpi/acpidump/acpidump.8
@@ -133,13 +133,25 @@
 .Nm :
 .Bl -tag -width indent
 .It Fl d
-Disassemble the DSDT into ASL using
+Concatenate the DSDT and the SSDT's into single image and disassemble the image into ASL using
 .Xr iasl 8
 and print the results to stdout.
 .It Fl t
 Dump the contents of the various fixed tables listed above.
 .It Fl h
 Displays usage and exit.
+.It Fl s
+Disassemble each of the DSDT and the SSDT's into ASL using
+.Xr iasl 8
+and print the results to stdout.
+This will avoid
+.Xr iasl 8
+error on disassembling concatenated image.
+If both
+.Fl d
+and
+.Fl s
+are specified, the last option is effective.
 .It Fl v
 Enable verbose messages.
 .It Fl f Ar dsdt_input
diff --git a/usr.sbin/acpi/acpidump/acpidump.c b/usr.sbin/acpi/acpidump/acpidump.c
--- a/usr.sbin/acpi/acpidump/acpidump.c
+++ b/usr.sbin/acpi/acpidump/acpidump.c
@@ -65,7 +65,7 @@
 	if (argc < 2)
 		usage(progname);
 
-	while ((c = getopt(argc, argv, "dhtvf:o:")) != -1) {
+	while ((c = getopt(argc, argv, "dhtvsf:o:")) != -1) {
 		switch (c) {
 		case 'd':
 			dflag = 1;
@@ -82,6 +82,9 @@
 		case 'o':
 			dsdt_output_file = optarg;
 			break;
+		case 's':
+			dflag = 2;
+			break;
 		case 'h':
 		default:
 			usage(progname);
@@ -136,7 +139,11 @@
 	if (dflag) {
 		if (vflag)
 			warnx("disassembling DSDT, iasl messages follow");
-		aml_disassemble(rsdt, sdt);
+		if (dflag == 1) {
+			aml_disassemble(rsdt, sdt);
+		} else {
+			aml_disassemble_separate(rsdt, sdt);
+		}
 		if (vflag)
 			warnx("iasl processing complete");
 	}