ANN ARBOR, Mich. — After a pandemic-fueled boom, U.S. pizza sales appear headed back to earth.

Domino’s and Papa John’s pizza chains both said Thursday that their same-store sales lost steam in the fourth quarter compared to the huge increases they saw earlier in 2020. Same-store sales are expected to continue seeing percentage declines well into this year.

Pizza delivery remains popular, but diners’ choices are expanding, with more restaurants now offering delivery.

In a survey of 3,500 U.S. restaurant operators last fall, the National Restaurant Association found that 27% had added delivery from a third party like DoorDash, while 17% had added in-house delivery. Pizza could also be pressured as the pandemic eases and dining rooms reopen.

“We aren’t sure exactly what the new normal will look like,” Domino’s CEO Ritch Allison said Thursday during a conference call with analysts.