Nigeria’s President Muhammadu Buhari on Wednesday chaired his first cabinet meeting since returning from sick leave in Britain this month.

Buhari returned to Nigeria on Aug. 19 after more than three months in London for treatment for an undisclosed ailment.

Last week he cancelled a cabinet meeting, raising concerns that the president, criticised for inertia by his opponents, was returning to his former ways, when he worked from home and missed weekly cabinet meetings.

The refusal to disclose details of Buhari’s illness has caused speculation about whether the 74-year-old is well enough to run Africa’s most populous country and biggest economy.

After returning form his first stint of medical leave in Britain on March 10, Buhari had reduced his working day to a few hours, diplomats and government sources said at the time.

In contrast, since his return this month, Buhari’s office has been releasing a flurry of photos and statements from the president’s engagements, like meetings with his vice president, heads of the military and economic ministers and the central bank.

Now, more than halfway through the president’s first four-year term, many Nigerian politicians are eyeing the 2019 elections.

Some politicians and diplomats privately wonder whether Buhari will be fit to run again.

If Buhari does not contest the election, that could spark a leadership race within his ruling party, the All Progressives Congress, or even a dissolution of the party if members cannot agree on a candidate, those people said.