wu_ftp ignores password aging

[Infra team member]

Hi folks,
I have a little question about wu_ftp and password aging.
System: 11.11, wu_ftp version 2.6.1

All users are set up with password ageing enabled.
They got also ftp enabled in a chroot env. and for the security point of view it seems to be acceptable, because when the password is expired for the shell, the user have to change the password and normally they work on the shell.
For users who gets only the ftp possibility with a e.g. /etc/noshell in the passwd and a password ageing occurs, wu_ftp is still ignoring it and it's using the old password.
How could it be handled to get it more secure or is there a parameter not set which I not be aware?

Thanks in advance.