Sugers effect on O.G

Hi All
I have used BeerSmith with great pleasure for about half a year now. I just recently found a recipe for a Belgian triple, where 1 kg of sugar is added after 4 days of fermentation.
I cannot see hove the effect of sugar is accounted for in regards of O.G / ABV in BeerSmith?

BeerSmith counts all fermentables in the OG and abv predictions. You should see a difference if you set the sugar addition to 0 kg.