diff --git a/sys/dev/adb/adb_mouse.c b/sys/dev/adb/adb_mouse.c
index 09f36413617..f602f1cd08d 100644
--- a/sys/dev/adb/adb_mouse.c
+++ b/sys/dev/adb/adb_mouse.c
@@ -46,7 +46,7 @@
 
 #include "adb.h"
 
-#define CDEV_GET_SOFTC(x) devclass_get_softc(adb_mouse_devclass, dev2unit(x) & 0x1f)
+#define CDEV_GET_SOFTC(x) (x)->si_drv1
 
 static int adb_mouse_probe(device_t dev);
 static int adb_mouse_attach(device_t dev);
@@ -236,6 +236,7 @@ adb_mouse_attach(device_t dev)
 	sc->cdev = make_dev(&ams_cdevsw, device_get_unit(dev),
 		       UID_ROOT, GID_OPERATOR, 0644, "ams%d", 
 		       device_get_unit(dev));
+	sc->cdev->si_drv1 = sc;
 
 	adb_set_autopoll(dev,1);