( CNN) Turkey voted Sunday on a referendum designed to hand the country’s President Recep Tayyip Erdogan sweeping powers.

Official results have not yet been released, and the opposition promised to tournament at least a third of the votes cast. But unofficial results from a state-run agency prove Erdogan winning by a small margin, with 99.8% of the ballots counted.

Here’s what stands to change in Turkey if the “yes” vote on the referendum becomes official.