When using cl-sdl2 and textinput event, I get an integer instead of a string. How to get the associated text ?

[...]
(sdl2:with-event-loop (:method :poll)
  (:textinput (:text text)
    (print text)  ; this is a number
    (print (code-char text))  ; ok for ASCII characters only ?
    (finish-output)))```

If I hit the "b" key, text is 98 and (code-char text) is #b, which is correct.
If I hit the "é" or "à" key, text is -61 (in both cases) and code-char signals an error, because -61 is not a valide code.

Shouldn't sdl/cl-sdl2 convert the input into string ?
How to get the string ?