QML Dialog: title cannot be set dynamically

Dialog {
    function newTitle(){
            return "new text";
        }
    id: textDialog
    visible: true
    title: newTitle() // Does not work
// title : "title123" //This works fine
    onAccepted: {console.log(title)}
    width:500
    contentItem.width: 500;
    contentItem.implicitWidth: 500;
        Label {
            text: newTitle()
            anchors.fill: parent
            wrapMode: Text.WrapAtWordBoundaryOrAnywhere
        }
}