Freeradius: change user passwords through pam_radius

Dear, I have a Linux box authenticating SSH users against Freeradius. It works OK. When the users go into the Linux box via SSH, I need them to change their own radius passwords. For this reason, I edited the /etc/pam.d/passwd file as follow: passwordsufficient pam_radius_auth.so above the following line password include system-auth