Brett Favre is no stranger to concussions, and he wants to prevent them in kids.

The 51-year-old ex-NFL quarterback encouraged parents to keep their kids out of tackle football until they turn 14 years old in a public service announcement released Tuesday with the Concussion Legacy Foundation.

Research from Boston University shows that for every year a person plays tackle football, their risk of developing chronic traumatic encephalopathy (CTE), a devastating degenerative brain disease, increases 30%.

Favre has spoken previously about discouraging kids from playing tackle football. In 2018, he said he’d support a theoretical law to ban tackle football for kids under 12. Favre also said he’d rather see his own grandchildren play a different sport. In the video, he encouraged youngsters to play flag football.