Earlier, during Cao Pi's reign, Sima Yi had warned Cao Pi that Meng Da, a former Shu general who had defected to Wei, was untrustworthy, but Cao Pi ignored him. He was proven right after Cao Pi's death, as towards the end of 227, Sima Yi received news that Meng Da was planning to rebel against Wei and return to Shu, and so, according to the "Weilüe", he had sent his adviser Liang Ji () to investigate Meng Da's case while urging Meng Da to visit the Wei capital Luoyang to attend to court, which alarmed the latter and finally convinced him to rebel.