diff --git a/docs/tools/qemu-nbd.rst b/docs/tools/qemu-nbd.rst
index faf6349ea5..329f44d989 100644
--- a/docs/tools/qemu-nbd.rst
+++ b/docs/tools/qemu-nbd.rst
@@ -197,7 +197,9 @@ driver options if :option:`--image-opts` is specified.
 
 .. option:: -v, --verbose
 
-  Display extra debugging information.
+  Display extra debugging information. This option also keeps the original
+  *STDERR* stream open if the ``qemu-nbd`` process is daemonized due to
+  other options like :option:`--fork` or :option:`-c`.
 
 .. option:: -h, --help