libpam-pwquality not working in Ubuntu 16.04

I installed libpam-pwquality:

sudo apt-get install libpam-pwquality

And configured /etc/pam.d/common-password:

password        requisite                       pam_pwquality.so retry=3 minlen=10

password        [success=1 default=ignore]      pam_unix.so obscure use_authtok try_first_pass sha512
password        required                        pam_deny.so
password        required                        pam_permit.so

Then when I ran passwd, I could still set a password of 2 or 3 characters. What was missing?