Gitlab CE DB-migration requires GitlabShell 3.6 but Update tells to install 3.5

I've just updated our local Gitlab CE instance using the upgrade-guide at https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/update/8.11-to-8.12.md

When I ran then db:migrate-task from step 7 I got the following message:

$ sudo -u git -H bundle exec rake db:migrate RAILS_ENV=production
WARNING: This version of GitLab depends on gitlab-shell 3.6.0, but you're running 3.5.0. Please update gitlab-shell.

git tag in the gitlab-shell-directory only show tags up to v3.5.0, no 3.6-tag. gitlab-shell is on commit c6d8af599dc797ec8ba7874380abad393b439c9e

The gitlab-folder itself is on commit e614a34d

Somethings smelly here....