diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -671,11 +671,9 @@
     if (AcpiGbl_FADT.Flags & ACPI_FADT_RESET_REGISTER)
 	sc->acpi_handle_reboot = 1;
 
-#if !ACPI_REDUCED_HARDWARE
     /* Only enable S4BIOS by default if the FACS says it is available. */
     if (AcpiGbl_FACS != NULL && AcpiGbl_FACS->Flags & ACPI_FACS_S4_BIOS_PRESENT)
 	sc->acpi_s4bios = 1;
-#endif
 
     /*
      * Probe all supported ACPI sleep states.  Awake (S0) is always supported.