diff --git a/sys/dev/acpica/acpi_cpu.c b/sys/dev/acpica/acpi_cpu.c
index 8015af9234c..2a2387b2b90 100644
--- a/sys/dev/acpica/acpi_cpu.c
+++ b/sys/dev/acpica/acpi_cpu.c
@@ -201,7 +201,7 @@ static driver_t acpi_cpu_driver = {
     sizeof(struct acpi_cpu_softc),
 };
 
-extern devclass_t cpu_devclass;
+static devclass_t cpu_devclass;
 DRIVER_MODULE(cpu, acpi, acpi_cpu_driver, cpu_devclass, 0, 0);
 MODULE_DEPEND(cpu, acpi, 1, 1, 1);