diff --git a/sys/cam/scsi/scsi_da.c b/sys/cam/scsi/scsi_da.c
index eb118e5026c1c..a08288480fcbe 100644
--- a/sys/cam/scsi/scsi_da.c
+++ b/sys/cam/scsi/scsi_da.c
@@ -2542,6 +2542,7 @@ daregister(struct cam_periph *periph, void *arg)
 		
 	/* Predict whether device may support READ CAPACITY(16). */
 	if (SID_ANSI_REV(&cgd->inq_data) >= SCSI_REV_SPC3 &&
+	    cpi.transport != XPORT_USB &&
 	    (softc->quirks & DA_Q_NO_RC16) == 0) {
 		softc->flags |= DA_FLAG_CAN_RC16;
 	}