Custom name for a template's temporary file name?

Hi

I'm trying to verify systemd unit files that we deploy with the
template module like this:

- name: Add systemd unit for our service
  become: true
  template:
    src: my.service.j2
    dest: "/lib/systemd/system/my.service"
    mode: "0644"
    validate: systemd-analyze verify %s

But this fails with:

Failed to prepare filename
/home/admin/.ansible/tmp/ansible-tmp-1624873742.536465-92105-76192242530114/source:
Invalid argument

This is because 'systemd-analyze verify' insists on the service file
to have a '.service' extension.
I've confirmed this by manually running things:

cd /home/admin/.ansible/tmp/ansible-tmp-1624873742.536465-92105-76192242530114/
cp source source.service

systemd-analyze verify source
Failed to prepare filename source: Invalid argument
echo $?
1

systemd-analyze verify source.service
echo $?
0

Is there some way to force the tmpfiles that are used by the template
module to have a certain extension?

Thx!

Dick