Despite a 2018 deal bringing South Sudan’s main warring parties into a ceasefire and unity government, a rebellion in the southern multi-ethnic Equatoria region fights on. Its leader, Thomas Cirillo, rejects the agreement, saying it fails to address his peoples’ core grievances, while calling for greater autonomy from the centre. On-and-off fighting is cutting a swathe of destruction in Equatoria, including south and west of the capital Juba, displacing hundreds of thousands of people into neighbouring countries and obstructing South Sudan’s path out of war and toward a more viable future. Mediators and external powers should press Cirillo and South Sudanese President Salva Kiir to broaden the existing peace deal by fulfilling the bespoke ceasefire agreement between them. Cirillo should join the country’s constitution-making process. Parties also should support a grassroots process to address local grievances.