Earlier this week, Transportation Secretary Sean Duffy announced that air travel was likely going to get worse in the coming weeks thanks to the government shutdown. Now, we know what that means: flights are gonna be canceled.

According to ABC, Duffy said that if the shutdown continues, there will be “mass flight delays,” “mass cancelations,” and possibly the closing of “certain parts of the airspace.”

Why? Two reasons: understaffing and a lack of pay. There was already an air traffic control shortage before the shutdown, and now that they’re not getting paid, the desire for airport workers to come in — or actually care once they’re there — is pretty low. ABC reports that nearly half of major air traffic control facilities have staff shortages, and in certain areas like New York, 80% of staff have called out.

So, if you planned to travel for Thanksgiving by plane … well, better find a cheap bus ticket as a backup!