Kotlin v2.4.20 released!

NewsBot · 7 September 2026 12:25

Kotlin v2.4.20 has been released.

Changelog

Analysis API

KT-86546 Check suspicious when over ConeKotlinType in ConeTypeCompatibilityChecker

KT-85418 Implement an API for accessing deserialized file annotations in Analysis API

KT-74448 K2. False positive MISSING_DEPENDENCY_SUPERCLASS in LinkedListTest.kt, kotlinx.coroutines

KT-85856 containingSymbol of constructor property differs for local and non-local classes

KT-65417 K2 IDE: KTOR false positive expect-actual matching error on enum class because of implicit clone() in non-JVM source sets

Analysis API. Code Compilation

KT-76457 K2 IDE / KMP Debugger: KISEWA “Cannot compile a common source without a JVM counterpart” on evaluating inline fun from common module inside jvm

Analysis API. FIR

KT-70552 No expects for actual

KT-69727 K2 IDE. Wrong error in the editor on calling clone function of actual enum instance in non-jvm platform

KT-69726 FP errors on declaring fun clone() in actual enum in not-jvm source-set

KT-86014 Types are broken after remove parameter through change signature

KT-86363 KotlinIllegalArgumentExceptionWithAttachments: No dangling modifier found on companion blocks

KT-86147 Drop kotlin.parallel.resolve.under.global.lock registry key

KT-85543 Avoid lazy resolve for the contracts phase if no constracts might…

Link: Release Kotlin 2.4.20 · JetBrains/kotlin · GitHub