Marathons are tough. They're even tougher when the car guiding runners goes off course—twice—and makes the race longer than it should be. Organizers of the Belfast City Marathon are apologizing to runners after they say their route ended up being one-third of a mile too long because of that "human error," reports the BBC. The discrepancy might actually be worse, closer to a half-mile, according to a tweet cited by the Guardian. Race organizers say they will (somehow) adjust runners' times to "reflect the correct distance." The marathon is an annual tradition, but the course had been reconfigured this year to be flatter and to produce faster times. When it was over, runners began complaining that their personal GPS devices clocked more than the usual 26.2 miles. (More marathon stories.)