(KERO) — California will reinstate a mandatory indoor mask requirement starting Wednesday, Dec. 15th and running through Jan. 15, 2020, the state announced Monday.

California Health and Human Services Agency Secretary Dr. Mark Ghaly made the announced on a conference call to the media Monday afternoon.

In addition, the state is tightening restrictions on unvaccinated people who are attending mega events. For all events with more than 1,000 attendees, if you are unable to show proof of vaccination, you must show proof of an antigen test within the previous 24 hours, or a PCR test within the previous 48 hours (the current rule is any test within the previous 72 hours). Dr. Ghaly cites the availability of testing for the tightening of the window.

The state is also recommending that all travelers who enter California test themselves 3-5 days after arriving in the state.