They fell out last year when the 28-year-old Perry disapproved of Rihanna getting back together with rapper Chris Brown, reported Sun Online.
"Katy and Rihanna have both done the Hawaii and Cabo-type trips to Mexico before, so this time they're thinking something a bit different, like a safari in Africa.
They want somewhere where they can have amazing experiences but still get drunk," said a source.
Pics: Prabhas, Tamannaah Bhatia at 'Baahubali 2' first look launch at MAMI
'Ae Dil Hai Mushkil' photos: Aishwarya, Anushka, Karan get candid at MAMI
Photos: Huma Qureshi, Neha Dhupia and other celebs at MAMI
Photos: Amy Jackson, Daisy Shah at Mumbai airport
Photos: Sridevi, Irrfan and other celebs at 'Mughal-e-Azam' screening