Pearson Airport says operations are back to normal after warning travellers about check-in delays this morning due to an IT upgrade.

In a tweet sent out Wednesday, the Toronto-area airport said the upgrade caused certain systems to go in to “recovery mode.”

The issue resulted in “slightly longer than normal” check-in times for airline passengers.

“We apologize for the impact this may have on your journey and appreciate your patience,” the airport wrote in the tweet.

At around 9:45 a.m., the airport confirmed that the issue had been resolved.

"We thank travellers for their patience this morning as we upgraded our systems for a better experience," the airport said. "As always, we suggest you check your flight status with your airline before heading to the airport."