One Super Bowl ad found its way into some viewers’ homes during Sunday night’s big game.
During the Super Bowl on Sunday, Google GOOGL aired a one-minute ad promoting its Google Home smart home appliance. The ad shows people using the device to turn on lights, check the weather, translate phrases into Spanish, and more.
But according to several Google Home users who took to Twitter TWTR during the game, it also activated Google Homes sitting in rooms where people were watching the ad.
Get Data Sheet, Fortune's technology newsletter
Google Home was released last year as a competitor to the Amazon Echo. And like the Echo, it’s designed to be activated with a simple vocal command: “OK, Google.” The ad on Sunday showed several people saying “OK, Google” to issue their commands. According to affected Google Home users, the statements were loud enough in their rooms for the appliance, which is always listening to the starter command, to activate. (“Hey, Google,” can also activate the device, but wasn’t said in the ad.)
“Google Home commercial kept setting mine off,” Twitter user Bill Radjewski said on Sunday, according to tech news site The Verge, which earlier reported on the incident. Several others reported the same, though it’s unclear if any of the ad’s commands actually caused the appliance to interact with the smart home’s devices.