(NewsNation) — An airline mistook a 100-year-old for an infant due to a software limitation, leading to confusion at the airport when she arrived to check in.

“I was born in 1923, so I put in 23” in the year field, Mildred Kirschenbaum said.

Kirschenbaum told her story on Instagram, noting that airlines don’t allow her to enter her full birth year, so the systems mark her as an unaccompanied minor instead of a 100-year-old adult.

A travel agent from Florida, she’s started to factor in extra steps to address the confusion when she arrives to check in.

“I guess when they started, no one lived to a 100 to travel,” Kirschenbaum said.

Despite having her accurate year of birth on her passport, Kirschenbaum said she’s still usually greeted with confusion by staff.

“They’re bewildered,” she told NewsNation. “They do not know how to correct it.”

Kirschenbaum now budgets an extra hour to deal with airlines that have mistakenly recorded her as a minor rather than a centenarian. It’s advice she gives everyone who is flying, even those whose birthday is accurately recorded in the system.

“Slow down, don’t leave at the least minute and look at your watch and say, ‘I’m going to miss the plane,'” she said. “Take your time.”