Missouri Gov. Eric Greitens signed legislation Monday to make his state the 28th in the nation and the sixth in five years to adopt a right-to-work law, which prohibits workers from being forced to join or otherwise support a union as a condition of employment.

“Today, I signed Right to Work. This is about more jobs — Missourians are ready to work, and now our state is open for business!” Greitens tweeted. He had the signing event at an abandoned former warehouse in Springfield. He has two other signing ceremonies scheduled for the day.