Sir Frank Williams says he is not worried that Jean Todt will revert to his "hard" ways in his new role as FIA president.
Todt's former rival Williams, 67, knows the Frenchman best from his 14 years in charge of Ferrari.
"His methods weren't methods that we would use," he said in an interview with Arabian Business.
"He was then a difficult character," Williams added. "Very hard to get on with."
But Williams believes Todt, 63, has had to adopt a difference approach now that he is in charge of the sport's governing body.
"I met him recently (and) I think he has taken some charm lessons," he said, smiling.
Williams, meanwhile, described Todt's predecessor Max Mosley as "seriously unfairly clever" and "almost impossible to beat in any argument".