Some of the biggest names in tech are warning against a cyber attack that could, at least intermittently, shut down major portions of the internet in the United States on Election Day. News websites have been sounding an alarm about hacks of electronic voter rolls, voting booths, and even the power grid.

But what if a much more boring cyber attack—one that happened just two weeks ago—could affect you in a much simpler way?

Adam D’Angelo, the CEO of Quora and former Chief Technology Officer at Facebook, is worried about just that. And that’s why he has some advice before Nov. 8.

Find out where your precinct is before Election Day on Nov. 8. Write down the address. Print out or screenshot some directions to it. (You can do all of those things right here.)

You might not be able to access this information easily—especially if you’re in a rush next Tuesday morning—if the web is under the same kind of attack it’s encountered a few times before.

“Everybody should do screenshots on your phone, or just memorize it,” D’Angelo told The Daily Beast. “People who are campaigning, knocking on doors, those people should be prepared.”

Why? A well-targeted distributed denial of service (DDoS) attack to standard, everyday services like Google or Apple Maps could leave people who don’t know exactly where to vote without a way to know where to be—or how to get there.

Or as D’Angelo tweeted on Sunday night: “Many groups have the ability and incentive. (A) Maps outage alone could easily skew the election.”

“Among people who work in the internet industry, there’s a general awareness that there’s lots of ways that these groups could do DDoS attacks on Election Day. I think, basically, everyone knows that these groups are able to shut down different services at different times,” said D’Angelo.

“I think there’s also general awareness that some of these groups may be foreign governments or just hackers, kids—who knows—who have motivation to influence the election.”

On Oct. 21, major websites like Twitter, Netflix, and Reddit were crippled under the weight of three separate denial of service attacks, leaving them unreachable for parts of the day. The attack was completed by remotely hijacking devices like DVRs and CCTV cameras and overloading traffic to specific servers to shut them down.

National Intelligence Director James Clapper attributed the attack to a “non-state actor.” That means the attack happened without the coordination—and money—that a foreign government or other motivated nefarious actor could provide.

As Sam Altman, president of the startup accelerator YCombinator, told Mashable: “That attack on Dyn felt to me like a warm-up to something or a practice run. Like someone going after something very specific.”

That’s what has D’Angelo worried.

“It’s almost something I would expect to happen. There’s these incredible amounts of money that governments can pour into these programs. On this side, the NSA is a $10-billion-per-year agency,” said D’Angelo. “You saw last week, a bunch of kids can take down half the internet.”

There’s one reason, however, D’Angelo thinks this might not happen.

First, there’s no real way to know if this is going to “affect who actually votes by doing it.”

“This is purely theoretical. Is it possible to shut down a subset of services that skews the election one way or the other? I think that is probably true. I just don’t know the demographics,” he said. “For them, what’s the real impact?”

That’s why, he said, a large-scale shutdown might not happen. If a foreign actor or well-financed hacking sect is capable of shutting down the web most of the day, but they’ve already determined it’s not going to be to their benefit, why would they blow a perfectly good cyber weapon for nothing?

“It’s highly likely they could do it. The reason they wouldn’t is because they don’t want to waste their time with it,” he said.

In the meantime, there’s an easy way to firewall yourself: Look up where you’re voting right now. All you have to do is Google “where’s my precinct?” You can also check out the super useful yourfuckingpollingplace.com. Either one works.

“I definitely believe it’s possible to affect the number of people who turn out to vote. There’s a lot of data saying that when you make things a little bit harder, fewer people turn out,” said D’Angelo.

Don’t let yourself be one of those people. Click here and find your polling place before you’re scrambling—with or without internet access—on Election Day.