changing password with otp active

Hello to all

When I activate the otp-overlay I can login with my userpassword and the 6 digit token. But how can I change the password with otp activ?

Without otp I do "passwd" then giving the old password and then the new password twice and the password is changed

With opt I have to give the old password+6-digit. If I only giving the password the server complains immediately that the password is wrong. When I'm giving the old password plus the 6-digit, the server accepts the password. Then I can give the new password twice, but then I'm getting the massage: Server-message: Old password not accepted.

So how can an user change his password via commandline with otp active?

Thanks

Stefan