Hagia Sophia reverberated to a muezzin’s call to morning prayer from inside the 6th century Istanbul landmark for the first time in 85 years on Saturday.

The building in the city’s historic Sultanahmet district broadcast the azan from its minarets following Friday’s Laylat al-Qadr, or night of power, marking the first revelation of the Quran to the Prophet Muhammad.

The broadcast of the morning call to prayer from within Hagia Sophia 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.