Android Module specific libraries in Gradle

I have an android module , core, which I use in a few projects. The core module has unit tests (as it should). The core module also has dependencies on a few external jars. The module itself builds fine and I get a nice shiny AAR, but I can't build the tests. Gradle (dex, actually) complains that certain libs are included multiple times. The tests use a custom test runner and that is their only jar dependency.I have an android module , core, which I use in