Orvis Co., the 162-year-old retailer known for its outdoorsy catalogs, is following Walmart Inc. and Dick’s Sporting Goods Inc. in tightening firearms restrictions.

The company will now require shoppers to be 21 to buy shotguns, the company announced Tuesday on Twitter.

But customers age 18 to 21 will get an exemption if they have proof of completing a hunter education and safety course, Orvis said.

@shannonrwatts We're raising our min. age for purchase of shotguns to 21. True to our commitment to safety & education, customers ages 18-21 can purchase a shotgun with proof that they've completed an official Hunter Education & Safety course. We do not sell assault-style rifles.

— The Orvis Company (@TheOrvisCompany) March 6, 2018

A wave of retailers have made changes to their gun policies in the wake of a school shooting last month in Parkland, Florida. Walmart and Dick’s also increased the minimum purchasing age to 21. And Dick’s stopped selling assault-style rifles at its Field & Stream stores.

Activists have also called on Bass Pro Shops to stop selling such weapons, which are known as modern sports rifles. The company hasn’t announced any changes, though Chief Executive Officer John Morris talked with representatives for families of those killed in the 2012 Sandy Hook school shooting.

Orvis, meanwhile, is focused on shotguns and gear for bird hunting and clay-pigeon shooting.

“We do not sell assault-style rifles,” the Vermont-based company said.