Custom Cursor for ContainerSplitter

Hey,

I´m trying to change the cursor of the ContainerSplitter with a style.

        <Style  TargetType="{x:Type docking:ContainerSplitter}">
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="Background" Value="Yellow" />
                    <Setter Property="Cursor" Value="None"/>
                </Trigger>
            </Style.Triggers>
        </Style>

 The background is changing if the mouse is over but the cursor is not.

What do I have to do to change the cursor, too?