diff --git a/usr.sbin/acpi/acpidump/acpi.c b/usr.sbin/acpi/acpidump/acpi.c
index 119f74c196d..c9e2d5745d5 100644
--- a/usr.sbin/acpi/acpidump/acpi.c
+++ b/usr.sbin/acpi/acpidump/acpi.c
@@ -2547,7 +2547,7 @@ acpi_print_rsd_ptr(ACPI_TABLE_RSDP *rp)
 	printf(END_COMMENT);
 }
 
-static struct {
+static const struct {
 	const char *sig;
 	void (*fnp)(ACPI_TABLE_HEADER *);
 } known[] = {