QML item Button is displayed/handled as Qt Quick Controls Button although self-defined

Steps to reproduce:

• create a simple Qt Quick 1 project
• add a QML file named Button.qml
• use the Button item inside the main.qml

Current behavior:

• the Button item (inside main.qml) will get the ToolTip for the Button component of Qt Quick Controls
• outline displays the icon of the Qt Quick Controls button

Note: I'm not importing QtQuick.Controls and I'm only using QtQuick 1.1.