change and eject commands are not working on an overlay

From qemu monitor, 'change' and 'eject' commands are not working on a CD overlay.
'info block' returns:
  cd0-overlay0: /home/guillaume/test/cd0-overlay0 (qcow2)
    Attached to:      cd0-device
    Removable device: not locked, tray closed
    Cache mode:       writeback, ignore flushes
    Backing file:     /home/guillaume/test.iso (chain depth: 1)

But 'eject cd0-overlay0' returns:
  Device 'cd0-overlay0' not found
I also tried 'cd0-device' and 'cd0'.

Same problem with 'change' command.