--- src/sys/dev/usbmisc/umass/umass.c	2008/02/10 00:01:03	1.37
+++ src/sys/dev/usbmisc/umass/umass.c	2008/05/18 20:30:23	1.38
@@ -2696,6 +2696,7 @@ umass_cam_attach_sim(struct umass_softc
 				DEVNAME_SIM,
 				sc /*priv*/,
 				device_get_unit(sc->sc_dev) /*unit number*/,
+				&sim_mplock,
 				1 /*maximum device openings*/,
 				0 /*maximum tagged device openings*/,
 				devq);