diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7851d669e..be7ce7a7e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # CHANGELOG
 
+## 0.4.0
+> Published 6 June 2024
+
+### Features
+- Updated Kotlin to 2.0 [#327](https://github.com/Kotlin/kotlinx-io/pull/327)
+
 ## 0.3.5
 > Published 17 May 2024
 
diff --git a/README.md b/README.md
index 245f387b5..83c1a6a14 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 [![JetBrains incubator project](https://jb.gg/badges/incubator.svg)](https://confluence.jetbrains.com/display/ALL/JetBrains+on+GitHub)
 [![GitHub license](https://img.shields.io/github/license/kotlin/kotlinx-io)](LICENSE)
 [![Download](https://img.shields.io/maven-central/v/org.jetbrains.kotlinx/kotlinx-io-core)](https://central.sonatype.com/artifact/org.jetbrains.kotlinx/kotlinx-io-core/)
-[![Kotlin](https://img.shields.io/badge/kotlin-1.9.24-blue.svg?logo=kotlin)](http://kotlinlang.org)
+[![Kotlin](https://img.shields.io/badge/kotlin-2.0-blue.svg?logo=kotlin)](http://kotlinlang.org)
 [![TeamCity build](https://img.shields.io/teamcity/build/s/KotlinTools_KotlinxIo_BuildAggregated.svg?server=http%3A%2F%2Fteamcity.jetbrains.com)](https://teamcity.jetbrains.com/viewType.html?buildTypeId=KotlinTools_KotlinxIo_BuildAggregated&guest=1)
 [![KDoc link](https://img.shields.io/badge/API_reference-KDoc-blue)](https://kotlin.github.io/kotlinx-io/)
 
@@ -48,7 +48,7 @@ repositories {
 Add the library to dependencies:
 ```kotlin
 dependencies {
-    implementation("org.jetbrains.kotlinx:kotlinx-io-core:0.3.5")
+    implementation("org.jetbrains.kotlinx:kotlinx-io-core:0.4.0")
 }
 ```
 
@@ -58,7 +58,7 @@ kotlin {
     sourceSets {
         commonMain {
             dependencies {
-                implementation("org.jetbrains.kotlinx:kotlinx-io-core:0.3.5")
+                implementation("org.jetbrains.kotlinx:kotlinx-io-core:0.4.0")
             }
         }
     }
@@ -72,7 +72,7 @@ Add the library to dependencies:
 <dependency>
     <groupId>org.jetbrains.kotlinx</groupId>
     <artifactId>kotlinx-io-core-jvm</artifactId>
-    <version>0.3.5</version>
+    <version>0.4.0</version>
 </dependency>
 ```
 
diff --git a/gradle.properties b/gradle.properties
index 21f832ac0..3554f8341 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -4,7 +4,7 @@
 #
 
 group=org.jetbrains.kotlinx
-version=0.3.6-SNAPSHOT
+version=0.4.0-SNAPSHOT
 kotlin.code.style=official
 org.gradle.jvmargs=-Xmx4G
 nativeBenchmarksEnabled=true