diff --git a/sys/dev/usb/storage/umass.c b/sys/dev/usb/storage/umass.c
index 7e305ad4fdc3..546d524cdf35 100644
--- a/sys/dev/usb/storage/umass.c
+++ b/sys/dev/usb/storage/umass.c
@@ -2094,6 +2094,7 @@ umass_cam_attach_sim(struct umass_softc *sc)
 
 	if (xpt_bus_register(sc->sc_sim, sc->sc_dev,
 	    sc->sc_unit) != CAM_SUCCESS) {
+		cam_sim_free(sc->sc_sim, /* free_devq */ TRUE);
 		mtx_unlock(&sc->sc_mtx);
 		return (ENOMEM);
 	}