Previously, building multiplatform projects using Gradle relied on separate Gradle plugins per targeted platform: `kotlin-platform-common`, `kotlin-platform-js`, and `kotlin-platform-jvm`.

[Starting from Kotlin 1.3](https://discuss.kotlinlang.org/t/kotlin-1-3-m2-new-multiplatform-projects-model/9264), this is now unified using one `kotlin-multiplatform` plugin. [The current documentation specifies how to set up multiplatform projects using this approach](https://kotlinlang.org/docs/reference/building-mpp-with-gradle.html#setting-up-a-multiplatform-project).

However, in my project I have multiple multiplatform projects with some dependencies between them. With the old multiplatform configuration, each different platform is a separate module and adding dependencies between projects required adding project references in each platform-specific module to corresponding modules in the other project: e.g., `project(':some-library:some-library-js')` to add a dependency to the JS module from within another JS module.

While migrating to the new multiplatform configuration, I now need to add a dependency from a project configured using the old configuration method to a project configured using the new `kotlin-multiplatform` plugin.

**Given that platform-specific modules are now specified and managed by the new plugin, how do I go about this?**