diff --git a/sys/amd64/acpica/acpi_machdep.c b/sys/amd64/acpica/acpi_machdep.c
index a418b7195045..352842f99100 100644
--- a/sys/amd64/acpica/acpi_machdep.c
+++ b/sys/amd64/acpica/acpi_machdep.c
@@ -40,8 +40,7 @@ acpi_machdep_init(device_t dev)
 {
 	struct	acpi_softc *sc;
 
-	sc = device_get_softc(dev);
-
+	sc = devclass_get_softc(devclass_find("acpi"), 0);
 	acpi_install_wakeup_handler(sc);
 
 	if (intr_model != ACPI_INTR_PIC)