Espresso Stout Brew Question

I brewed a stout a few weeks ago, racked to the secondary this weekend and added espresso.
During the initial boil i seemed to lose a lot of liquid and had to add a solid gallon of water to the primary after the fact to get up over 5 gallons. When i racked i noticed the stout seemed a bit more watery than i would like it. I'm considering adding some maltodextrin either into the secondary or at bottling.

Any thoughts or suggestions to 'thicken' the stout a bit?

Thanks

At this late stage, no. Next time, don't add water, add some oats or a little chocolate wheat to your recipe. Then mash hotter, 156 F.

You could possibly add some lactose to thicken the body a bit and it would probably be a welcome addition in a coffee stout. Otherwise, I wouldn't do anything to adjust it now that primary fermentation has finished.