Yeah, the Kamik Waterbug 5 boots do tend to run a bit small.

According to our research, folks have noted that they can feel pretty snug, especially if you're wearing thick socks, which you probably will in colder weather.

Lots of people suggest going a size up for a more comfortable fit. The insulated liner also makes them feel tighter, so that's something to keep in mind too.

One person mentioned that their boots felt really tight with thicker socks, and they recommended going up at least one or two sizes.

Overall, based on what we've found, it's a good idea to order a size bigger if you're planning to use these in the winter with thicker socks. It should give you a more comfortable fit and keep your feet warm.