diff --git a/sys/powerpc/mambo/mambo.c b/sys/powerpc/mambo/mambo.c
index 6b57d052943a..528f29fed83e 100644
--- a/sys/powerpc/mambo/mambo.c
+++ b/sys/powerpc/mambo/mambo.c
@@ -75,9 +75,7 @@ static driver_t mambobus_driver = {
 	0
 };
 
-static devclass_t mambobus_devclass;
-
-DRIVER_MODULE(mambo, ofwbus, mambobus_driver, mambobus_devclass, 0, 0);
+DRIVER_MODULE(mambo, ofwbus, mambobus_driver, 0, 0);
 
 static int
 mambobus_probe(device_t dev)
diff --git a/sys/powerpc/mambo/mambo_disk.c b/sys/powerpc/mambo/mambo_disk.c
index 935aeab636bc..bc8c46772ccb 100644
--- a/sys/powerpc/mambo/mambo_disk.c
+++ b/sys/powerpc/mambo/mambo_disk.c
@@ -274,6 +274,5 @@ static driver_t mambodisk_driver = {
 	mambodisk_methods,
 	sizeof(struct mambodisk_softc),
 };
-static devclass_t mambodisk_devclass;
 
-DRIVER_MODULE(mambodisk, mambo, mambodisk_driver, mambodisk_devclass, 0, 0);
+DRIVER_MODULE(mambodisk, mambo, mambodisk_driver, 0, 0);