Is there a way to include additional dependencies or jar file in a Spring bootable jar?

I’m using the spring-boot-maven-plugin outside of a spring project to generate a bootable jar. This works fine, except the project also generates a jar file (not classes) that need to be included in the bootable jar as well.

The plugin’s includes configuration parameter seems to filter the existing dependency set instead of adding to it.

The includeSystemScope won’t work, because if I declare the dependency with scope system it needs to present at compile it. Which it is not (in that phase). Scope provided could work, but won’t be picked up by the includeSystemScope.

Is there a way to add an additional jar file to the bootable jar?