juju 1.17.2 doesn't pass command line options to ssh

In juju 1.16.6, this works:

$ juju ssh ubuntu/0 -q ls /
bin boot dev etc home initrd.img lib lib64 lost+found media mnt opt proc root run sbin selinux srv sys tmp usr var vmlinuz

juju 1.16.6 calls ssh like this:
20647 execve("/usr/bin/ssh", ["ssh", "-l", "ubuntu", "-t", "-o", "StrictHostKeyChecking no", "-o", "PasswordAuthentication no", "10.55.32.243", "-q", "ls"], [/* 109 vars */] <unfinished ...>

The help says:
"Any extra parameters are passsed as extra parameters to the ssh command."

It doesn't work in juju 1.17.2:
$ juju ssh ubuntu/0 -q ls
Warning: Permanently added '10.55.32.243' (ECDSA) to the list of known hosts.
bash: -q: invalid option
Usage: bash [GNU long option] [option] ...
 bash [GNU long option] [option] script-file ...
GNU long options:
 --debug
 --debugger
 --dump-po-strings
 --dump-strings
 --help
 --init-file
 --login
 --noediting
 --noprofile
 --norc
 --posix
 --protected
 --rcfile
 --restricted
 --verbose
 --version
Shell options:
 -irsD or -c command or -O shopt_option (invocation only)
 -abefhkmnptuvxBCHP or -o option
Connection to 10.55.32.243 closed.
ERROR exit status 2

juju 1.17.2 calls ssh like this:
20113 execve("/usr/bin/ssh", ["ssh", "-o", "StrictHostKeyChecking no", "-o", "PasswordAuthentication no", "-t", "ubuntu@10.55.32.243", "--", "-q", "ls"], [/* 109 vars */] <unfinished ...>

help says:
usage: juju ssh [options] <target> [<ssh args>...]
Any extra parameters are passsed as extra parameters to the ssh command.