TextInput not repained when enchMode changes

import Qt 4.7

Rectangle {
    width: 950
    height: 500

    TextInput {
        id: textInput
        anchors.centerIn: parent
        echoMode: TextInput.Normal
        text: "Click me to change to password mode"
        font.pixelSize: 30
    }

    color: textInput.echoMode == TextInput.Password ? "red" : "green"

    MouseArea {
        anchors.fill: parent
        onClicked: textInput.echoMode = TextInput.Password
    }
}