How to change mouseOver style

Hello,

I'm trying to override the background of a button when the mouse is over, but I can't get it to work.
I've tried several approaches, such as:

<Style TargetType="Button" BasedOn="{StaticResource {x:Type Button}}">
    <Style.Triggers>
        <Trigger Property="IsMouseOver" Value="True">
            <Setter Property="Background" Value="Red"/>
        </Trigger>
    </Style.Triggers>
</Style>

Thanks,

Benjamin.