diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinUsages.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinUsages.kt
index 324e0689522..94564efaebd 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinUsages.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinUsages.kt
@@ -36,6 +36,7 @@ object KotlinUsages {
         when {
             platformType in jvmPlatformTypes -> JAVA_API
             platformType == common
+                    /** The kotlinExtension check below can be removed when legacy [KotlinPlatformCommonPlugin] is also removed. */
                     && project.kotlinExtension is KotlinMultiplatformExtension
                     && !project.isCompatibilityMetadataVariantEnabled -> KOTLIN_METADATA
             else -> KOTLIN_API