diff --git a/share/qtcreator/qmldesigner/welcomepage/CustomDialog.qml b/share/qtcreator/qmldesigner/welcomepage/CustomDialog.qml
index 76b3c4c8e70..3379ac7667a 100644
--- a/share/qtcreator/qmldesigner/welcomepage/CustomDialog.qml
+++ b/share/qtcreator/qmldesigner/welcomepage/CustomDialog.qml
@@ -37,6 +37,6 @@ Dialog {
     }
 
     Overlay.modal: Rectangle {
-        color: Color.transparent(Constants.currentDialogBackground, 0.5)
+        color: Qt.alpha(Constants.currentDialogBackground, 0.5)
     }
 }