QML Slider: Negative values do not work as expected

Specifying a Slider with

            minimumValue: -100
            maximumValue: +100
            stepSize: 1

should result in a slider capable of moving from -100 to +100, but the UI shows 0 at the leftmost point, negative values are not visible.

This should either be supported or it should be stated that minimumValue can't be negative.