Index: head/sys/dev/acpica/acpi.c
===================================================================
--- head/sys/dev/acpica/acpi.c
+++ head/sys/dev/acpica/acpi.c
@@ -237,7 +237,8 @@
 };
 
 static devclass_t acpi_devclass;
-DRIVER_MODULE(acpi, nexus, acpi_driver, acpi_devclass, acpi_modevent, 0);
+EARLY_DRIVER_MODULE(acpi, nexus, acpi_driver, acpi_devclass, acpi_modevent, 0,
+    BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
 MODULE_VERSION(acpi, 1);
 
 ACPI_SERIAL_DECL(acpi, "ACPI root bus");