Crash on Alt + FX

Poezio crash when you press Alt + F[X]
Traceback (most recent call last):
File "poezio.py", line 91, in
main()
File "poezio.py", line 86, in main
gui.main_loop() # Refresh the screen, wait for user events etc
File "/home/mathieui/poezio/src/gui.py", line 444, in main_loop
char=read_char(self.stdscr)
File "/home/mathieui/poezio/src/keyboard.py", line 54, in read_char
return "M-"+chr(first)
TypeError: an integer is required
launch.sh: line 3: 7752 Abandon python3 poezio.py "$@"