As runners set out on what was meant to be a 21km half-marathon in Bangkok last weekend, many were surprised to find a significant addition to their route.

Thanks to an error by organizers for the Standard Chartered Bangkok Marathon, the run ended up at a significantly longer 28km, reports the Bangkok Post.

Many runners complained that the additional length ruined the experience since they had trained specifically for a half-marathon.

“It added more than 3km to each lap, therefore more than 6km were added to the whole half-marathon,” Surapong Ariyamongkol, secretary general of the Athletic Association of Thailand told The Guardian. “We have rebuked the association but we could not do anything else.”

Ariyamongkol said race officials advised runners to make a U-turn at the wrong place.

Blame for the mistake ultimately fell on The Jogging Association of Thailand which issued a public apology on Monday.

“The association apologizes for the mistake,” Songrakm Kraison, its vice-president, told the Associated Press. “It will not happen again in the future.”

While the organizers drew some serious flack on their Facebook page, others got cheeky with their comments. One user said that the race should be rebranded as a “super half-marathon,” while another joked, “Hey, they increased the price this year, so you get more kilometers for your money.”

[Photo via Asher Isbrucker]