A muezzin – a man who calls Muslims to prayer from the minaret of a mosque – on Saturday, July 2 called to morning prayer (azan) from inside Hagia Sophia, the 6th century Istanbul landmark for the first time in 85 years, Anadulu Agency reports.

The building in the city’s historic Sultanahmet district broadcast the azan from within Hagia Sophia which is likely to reignite the controversy over the use of the building, which was designated a museum in 1935 under Mustafa Kemal Ataturk, the Republic of Turkey’s first president.

Although the prayer call has been played from Hagia Sophia’s minarets for the last four years, the muezzin has always chanted from a prayer room in the museum grounds rather than from inside the former mosque and cathedral.

Built as an Orthodox Christian basilica during the reign of Byzantine Emperor Justinian I in 537, the famous domed structure, known as Ayasofya in Turkish, was converted to a mosque following Sultan Mehmet II’s conquest of the city in 1453.

In recent years there have been calls to return the building to Muslim worship. Last month, the Greek government complained about the reciting of the Quran in Hagia Sophia during Ramadan.