Mobile boarding passes are a great way to both skip the hassle of printing out a ticket at home and avoid lines at check-in when you get to the airport. But Christine Sarkis of SmarterTravel has a pro tip that we would all do well to take: Don’t rely on a boarding pass that requires an Internet connection.

The most technologically advanced solution isn’t always the most reliable. While most airlines will send a link to a mobile version of your boarding pass, you might need WiFi or mobile data to access it—neither of which are always at their best inside an airport terminal. Sarkis once found herself standing at the front of the security line with a link to a webpage that wouldn’t load, and had to run outside to load her boarding pass before returning to security.

You don’t necessarily want to put the fate of your entire trip in the hands of a potentially fickle smartphone. If you’re using a link to your mobile boarding pass that your airline has emailed you, take a screenshot of it, so you can still scan it when you get to security or your gate if you can't load the page. Better yet, save an offline version to your Apple Wallet or PassWallet. When you save the ticket to your mobile passbook, you’ll get push notifications as the flight time draws near that give you easy access to the ticket from your notification screen.

[h/t SmarterTravel]