Erdogan signed a decree handing over Hagia Sophia to Turkey’s Religious Affairs Presidency and declaring it open to Muslim worship.

Turkey’s highest administrative court on Friday issued a ruling that paves the way for the government to convert Istanbul’s iconic Hagia Sophia — a former cathedral-turned-mosque that now serves as a museum — back into a Muslim house of worship.

The Council of State threw its weight behind a petition brought by a religious group and annulled a 1934 cabinet decision that turned the 6th-century building into a museum.

Dozens of people who awaited the court’s ruling outside the Hagia Sophia jubilantly chanted “Allah is great!” when the news came out. Orthodox Christians expressed deep dismay.