Last week, as the nation reckoned with the school shooting at a Florida high school that left 17 people dead, Dick’s Sporting Goods and Walmart decided to raise the minimum age for buying a firearm and ammunition to 21 from 18.

Now the retailers are being sued.

Tyler Watson, 20, alleges he encountered age discrimination when he tried to purchase a .22 caliber Ruger rifle on Feb. 24 — four days before the companies announced their new policies — at Field & Stream, an outdoors sports store in Medford, Ore., owned by Dick’s. In Oregon, state law allows residents to purchase firearms at age 18.

“He had heard something about the policy change but he didn’t expect to be denied service,” said Max Whittington, Watson’s lawyer. “He went in with the intent to buy a rifle, not to test the new policies.”

Tyler Watson is asking judges in the two counties to stop Dick’s and Walmart from “unlawfully discriminating against 18-, 19-, and 20-year-old customers” at their Oregon stores. He is also asking for an undisclosed amount of punitive damages and for his attorney fees to be paid.