Gingerbread Train Stations

For the past two years, I've been making Gingerbread Houses. I wouldn't call them professionally built, but I do try my hardest to make them stand up on there on. If anyone of you has made one or attempted to, you know exactly what I mean.

This year, I had some new train cookie cutters, so I decided to make my Gingerbread House into a Train Station. It all stood up except the roof! I tried numerous times to keep the roof "glued" on the sides of the walls of the house.