Manava Dharmashastra 11.157

11.157

māsikānnaṃ tu yo 'śnīyād asamāvartako dvijaḥ
sa trīṇy ahāny upavased ekāhaṃ codake vaset //

The atonement for partaking of (the meat of) carnivorous animals, of pigs, of camels, of cocks, of crows, of donkeys, and of human flesh, is a Tapta Krikkhra (penance).