I'm trying to sync from a direct repo to another direct repo but getting a non-fast-forward rejection:

    push v-crateris 
    Counting objects: 509, done.
    Delta compression using up to 4 threads.
    Compressing objects: 100% (455/455), done.
    Writing objects: 100% (509/509), 33.21 KiB | 4.74 MiB/s, done.
    Total 509 (delta 350), reused 0 (delta 0)
    remote: Resolving deltas: 100% (350/350), completed with 174 local objects.
    To v-crateris:/annex/Music
       c60621302..803920707  git-annex -> synced/git-annex
     ! [rejected]            annex/direct/master -> synced/master (non-fast-forward)
    error: failed to push some refs to 'v-crateris:/annex/Music'
    hint: Updates were rejected because a pushed branch tip is behind its remote
    hint: counterpart. Check out this branch and integrate the remote changes
    hint: (e.g. 'git pull ...') before pushing again.
    hint: See the 'Note about fast-forwards' in 'git push --help' for details.
    To v-crateris:/annex/Music
     ! [rejected]            master -> master (non-fast-forward)
    error: failed to push some refs to 'v-crateris:/annex/Music'
    hint: Updates were rejected because a pushed branch tip is behind its remote
    hint: counterpart. Check out this branch and integrate the remote changes
    hint: (e.g. 'git pull ...') before pushing again.
    hint: See the 'Note about fast-forwards' in 'git push --help' for details.

      Pushing to v-crateris failed.

      (non-fast-forward problems can be solved by setting receive.denyNonFastforwards to false in the remote's git config)
    failed

I tried setting `receive.denyNonFastforwards` to `false` as the message said, but it made no difference.
Both repos have `annex/direct/master` checked out.

What should I do to resolve this?