Scene from AssetBundle vs Scene from build

What happens if a scene in a downloaded assetbundle has the same name as one in the build? Eg if I have a scene in the build called "Demo", and then I download an assetbundle with another scene called "Demo". If I now load the "Demo" scene, which one will I get? Specifically, I would like to know if I can override a scene from the build with DLC or do I need to change the name of the scene in the AssetBundle to something else? (eg "Demo2")