Southwest Airlines says everything should be back to normal this morning after a system glitch on Sunday caused quite a headache for thousands of passengers, prompting hundreds of flight delays.

The airline told USAToday that as of 8:10 a.m. ET the problem had been fixed, and that it expects operations to return to their usual pace today. To that end, one of Southwest’s busiest airports Tweeted this morning that it was up and at’em.

About 450 flights were delayed starting early Sunday due to the unspecified computer glitch, which forced the airline’s staff to manually check in many passengers and write out boarding passes by hand. That led to super long lines for Southwest customers in airports around the country, from Detroit to Denver, Las Vegas to Baltimore.

Southwest had advised Monday customers to check in online and print their boarding passes at hime, or use mobile devices to display them instead of having the airline print them out at airport. It had also told customers to arrive at least two hours ahead of their scheduled flight.

The carrier is far from alone in its glitchiness: American Airlines, Spirit Airlines and United Airlines all suffered computer issues recently that snarled air travel for many travelers, and even the Federal Aviation Administration said it suffered a technical issues that led to flight headaches in August.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.