diff --git a/sys/dev/usb/usb_transfer.c b/sys/dev/usb/usb_transfer.c
index 67745cf4939..d41121ed3a0 100644
--- a/sys/dev/usb/usb_transfer.c
+++ b/sys/dev/usb/usb_transfer.c
@@ -1889,8 +1889,10 @@ usbd_transfer_submit(struct usb_xfer *xfer)
 	 */
 #if USB_HAVE_BUSDMA
 	if (xfer->flags_int.bdma_enable) {
+		USB_BUS_LOCK(bus);
 		/* insert the USB transfer last in the BUS-DMA queue */
 		usb_command_wrapper(&xfer->xroot->dma_q, xfer);
+		USB_BUS_UNLOCK(bus);
 		return;
 	}
 #endif