Sbt-rjs: Exclude files from uglification

Question

I use sbt-rjs with sbt-web to minimize and combine my javascripts during the build process. Part of this is trimming files that rjs processes using the uglify2 optimizer by default.

My quest is if I can exclude files from uglification, but still include them in the combined module? In particular, I want to skip already modified files in order to reduce the build time.