Regression from 2.0-beta15 release.
DomT4 at GitHub kindly reported this bug -- see https://github.com/kfogel/OneTime/issues/26.
(OneTime has moved over here to code.librehq.com GitLab, but there are still some open issue tickets and PRs over at GitHub. I haven't ported them all over; we'll just improvisatorily refer to them from here until they're closed. New tickets should be filed here, of course.)