diff --git a/Documentation/user/usb.rst b/Documentation/user/usb.rst
index 8396f38..b89d46b 100644
--- a/Documentation/user/usb.rst
+++ b/Documentation/user/usb.rst
@@ -266,3 +266,5 @@
   See :ref:`command_usbgadget` -a. (Default 0).
 ``global.usbgadget.fastboot_function``
   Function description for fastboot. See :ref:`command_usbgadget` -A [desc].
+``global.usbgadget.fastboot_bbu``
+  Export barebox update handlers. See :ref:`command_usbgadget` -b. (Default 0).