During the Ottoman period, St. John's was converted into the Mahmut Aga or Seytanoglu (Demon' Son) Mosque, at which time a small minaret was built in place of an earlier bell tower. Until recently, the area around St. John's was known as Seytanoglu. An Ottoman codex dating to 1854 records the mosque as dilapidated. After the Muslims left, the monument was declared "exchangeable" (available for use by Greeks refugees arriving from Asia Minor) and was sold to the Seferoglou or Seferiadis brothers.