non-ascii char in mount-point name ?

[Fulbert]

Hi,

  In my Guix system configuration file, I have a
(file-system …  (mount-point "/mnt/raté"))
with a 'é' (U+00E9) in its name, which gives the following error when
trying to reconfigure :
----
system: error: invalid character `�' in name 
`shepherd-file-system--mnt-raté.scm-builder'
----

Did I miss something or is it a Guix limitation ?