diff --git a/sys/dev/usb/umass.c b/sys/dev/usb/umass.c
index 916483ffb2c0..50b11cce22ea 100644
--- a/sys/dev/usb/umass.c
+++ b/sys/dev/usb/umass.c
@@ -241,7 +241,7 @@ typedef void (*transfer_cb_f)	(struct umass_softc *sc, void *priv,
 typedef void (*wire_reset_f)	(struct umass_softc *sc, int status);
 typedef void (*wire_transfer_f)	(struct umass_softc *sc, int lun,
 				void *cmd, int cmdlen, void *data, int datalen,
-				int dir, transfer_cb_f cb, void *priv);
+				int dir, u_int timeout, transfer_cb_f cb, void *priv);
 typedef void (*wire_state_f)	(usbd_xfer_handle xfer,
 				usbd_private_handle priv, usbd_status err);
 
@@ -527,6 +527,8 @@ struct umass_softc {
 	struct scsi_sense	cam_scsi_sense;
 	struct scsi_sense	cam_scsi_test_unit_ready;
 
+	int			timeout;		/* in msecs */
+
 	int			maxlun;			/* maximum LUN number */
 };
 
@@ -591,7 +593,7 @@ Static void umass_reset		(struct umass_softc *sc,
 Static void umass_bbb_reset	(struct umass_softc *sc, int status);
 Static void umass_bbb_transfer	(struct umass_softc *sc, int lun,
 				void *cmd, int cmdlen,
-		    		void *data, int datalen, int dir,
+		    		void *data, int datalen, int dir, u_int timeout,
 				transfer_cb_f cb, void *priv);
 Static void umass_bbb_state	(usbd_xfer_handle xfer,
 				usbd_private_handle priv,
@@ -606,7 +608,7 @@ Static int umass_cbi_adsc	(struct umass_softc *sc,
 Static void umass_cbi_reset	(struct umass_softc *sc, int status);
 Static void umass_cbi_transfer	(struct umass_softc *sc, int lun,
 				void *cmd, int cmdlen,
-		    		void *data, int datalen, int dir,
+		    		void *data, int datalen, int dir, u_int timeout,
 				transfer_cb_f cb, void *priv);
 Static void umass_cbi_state	(usbd_xfer_handle xfer,
 				usbd_private_handle priv, usbd_status err);
@@ -1125,7 +1127,7 @@ umass_setup_transfer(struct umass_softc *sc, usbd_pipe_handle pipe,
 	/* Initialiase a USB transfer and then schedule it */
 
 	(void) usbd_setup_xfer(xfer, pipe, (void *) sc, buffer, buflen, flags,
-			UMASS_TIMEOUT, sc->state);
+			sc->timeout, sc->state);
 
 	err = usbd_transfer(xfer);
 	if (err && err != USBD_IN_PROGRESS) {
@@ -1149,7 +1151,7 @@ umass_setup_ctrl_transfer(struct umass_softc *sc, usbd_device_handle udev,
 	/* Initialiase a USB control transfer and then schedule it */
 
 	(void) usbd_setup_default_xfer(xfer, udev, (void *) sc,
-			UMASS_TIMEOUT, req, buffer, buflen, flags, sc->state);
+			sc->timeout, req, buffer, buflen, flags, sc->state);
 
 	err = usbd_transfer(xfer);
 	if (err && err != USBD_IN_PROGRESS) {
@@ -1246,13 +1248,16 @@ umass_bbb_reset(struct umass_softc *sc, int status)
 
 Static void
 umass_bbb_transfer(struct umass_softc *sc, int lun, void *cmd, int cmdlen,
-		    void *data, int datalen, int dir,
+		    void *data, int datalen, int dir, u_int timeout,
 		    transfer_cb_f cb, void *priv)
 {
 	KASSERT(sc->proto & UMASS_PROTO_BBB,
 		("%s: umass_bbb_transfer: wrong sc->proto 0x%02x\n",
 			USBDEVNAME(sc->sc_dev), sc->proto));
 
+	/* Be a little generous. */
+	sc->timeout = timeout + UMASS_TIMEOUT;
+
 	/*
 	 * Do a Bulk-Only transfer with cmdlen bytes from cmd, possibly
 	 * a data phase of datalen bytes from/to the device and finally a
@@ -1759,12 +1764,15 @@ umass_cbi_reset(struct umass_softc *sc, int status)
 Static void
 umass_cbi_transfer(struct umass_softc *sc, int lun,
 		void *cmd, int cmdlen, void *data, int datalen, int dir,
-		transfer_cb_f cb, void *priv)
+		u_int timeout, transfer_cb_f cb, void *priv)
 {
 	KASSERT(sc->proto & (UMASS_PROTO_CBI|UMASS_PROTO_CBI_I),
 		("%s: umass_cbi_transfer: wrong sc->proto 0x%02x\n",
 			USBDEVNAME(sc->sc_dev), sc->proto));
 
+	/* Be a little generous. */
+	sc->timeout = timeout + UMASS_TIMEOUT;
+
 	/*
 	 * Do a CBI transfer with cmdlen bytes from cmd, possibly
 	 * a data phase of datalen bytes from/to the device and finally a
@@ -2391,7 +2399,7 @@ umass_cam_action(struct cam_sim *sim, union ccb *ccb)
 			}
 			sc->transfer(sc, ccb->ccb_h.target_lun, rcmd, rcmdlen,
 				     csio->data_ptr,
-				     csio->dxfer_len, dir,
+				     csio->dxfer_len, dir, ccb->ccb_h.timeout,
 				     umass_cam_cb, (void *) ccb);
 		} else {
 			ccb->ccb_h.status = CAM_REQ_INVALID;
@@ -2569,7 +2577,7 @@ umass_cam_cb(struct umass_softc *sc, void *priv, int residue, int status)
 				sc->transfer(sc, ccb->ccb_h.target_lun,
 					     rcmd, rcmdlen,
 					     &csio->sense_data,
-					     csio->sense_len, DIR_IN,
+					     csio->sense_len, DIR_IN, ccb->ccb_h.timeout,
 					     umass_cam_sense_cb, (void *) ccb);
 			} else {
 				panic("transform(REQUEST_SENSE) failed");
@@ -2669,7 +2677,7 @@ umass_cam_sense_cb(struct umass_softc *sc, void *priv, int residue, int status)
 					&rcmd, &rcmdlen)) {
 				sc->transfer(sc, ccb->ccb_h.target_lun,
 					     rcmd, rcmdlen,
-					     NULL, 0, DIR_NONE,
+					     NULL, 0, DIR_NONE, ccb->ccb_h.timeout,
 					     umass_cam_quirk_cb, (void *) ccb);
 			} else {
 				panic("transform(TEST_UNIT_READY) failed");