Guns N' Roses have been made to sign a 'Late Appearance' clause ahead of the Rock in Rio festival in Brazil.
The band - fronted by notoriously difficult frontman Axl Rose - will face a huge fine if they take to the stage late when they headline the festival on October 2, as they did when they appeared in 2001, according to festival vice-president Roberta Mediana.
She said: "Guns N' Roses' appearance this year was the hardest to arrange in the history of the festival.
"Bands are usually on time, but Guns is a different case. Lateness like the one in 2001- can make the public feel uncomfortable and cause them to possibly start a riot".
Guns N' Roses' 2001 show at Rock in Rio saw them take to the stage two hours late, and while the crowd waited patiently for them on that occasion, this has not been the case at other shows.
Last March, fans of the band rioted in Sao Paulo, Brazil after a private show was cancelled at the last minute, and in 2002 fans in Vancouver, Canada and Philadelphia in the US rioted when shows were cancelled on the day.
Also in 2010, organisers of the Reading festival in England pulled the plug on the band's PA, silencing them after they took to the stage an hour late and tried to overrun the event's curfew time by over half an hour.
Axl was escorted offstage by security after refusing to leave, and told the crowd: "We come here to play for you, but the cops and the promoters wanna f**k us in the ass."
The volatile frontman then threatened not to play the next night's show at the Leeds festival in protest.