Qantas has stopped its flights using Iraqi airspace in the wake of the MH17 disaster.
A Qantas spokesman said the airline has closely monitored flight paths over conflict zones since Malaysia Airlines flight MH17 was shot down over Ukraine two weeks ago.
He said Qantas flights from London to Dubai travel over Iraq at an altitude of 38,000 feet and 41,000 feet, well above the minimum altitude for commercial flights over Iraq.
But the US Federal Aviation Administration had just increased the minimum altitude from 20,000 feet to 30,000 feet, prompting a review of Qantas' London-Dubai route.
"Qantas has closely monitored the issue of flight paths over conflict zones, particularly in light of the MH17 tragedy, with safety our first priority," he said.
"We have no new information that alters our safety assessment of flying over Iraq, especially given the altitudes we maintain over this region.
"However given the various restrictions imposed by different governments in the past 24 hours, including by the United States FAA, Qantas has temporarily rerouted its flights within the Middle East to avoid Iraqi airspace. This change will apply until further information becomes available."
The change took effect on Thursday night and will add up to 10 minutes to the seven-hour flight.