View Shadow Breaks borderRadius

[OwenMelbz]

I've got the following TSS

".big_blue" : {
    borderRadius: 25,
    height: 50,
    width: '100%',
    color: '#fff',
    backgroundColor: Alloy.CFG.blue,
    shadow:{
            shadowRadius:10,
            shadowOpacity:1,
            shadowOffset:{x:2, y:2}
    }
}

However the moment I add the shadow on the radius on the view disappears, if i remove the shadow property, it returns.

Thanks