# Migrating to v15

## Important Notice (Android Only)

The original v15 guidance recommended Kotlin 2.0.0 to match its contemporary Android
build tools. That is not a general minimum for later releases.

For v17, use Kotlin 1.9.25 or newer. Google Mobile Ads Android SDK 25.4 ships Kotlin 2.3
metadata, so v17 applies a module-scoped metadata compatibility compiler flag when built
with Kotlin versions earlier than 2.3. Kotlin 2.3 and newer need no skip. See
[Android Kotlin compatibility](/#android-kotlin-compatibility) for details.