diff --git a/.idea/kotlinc.xml b/.idea/kotlinc.xml
index 76f63447..099097a5 100644
--- a/.idea/kotlinc.xml
+++ b/.idea/kotlinc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="KotlinJpsPluginSettings">
-    <option name="version" value="2.3.20" />
+    <option name="version" value="2.3.21-RC" />
   </component>
 </project>
diff --git a/build.gradle.kts b/build.gradle.kts
index 3046c340..e560dc5a 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -13,7 +13,7 @@ buildscript {
 
 allprojects {
     group = "com.rickclephas.kmp"
-    version = "1.0.2-idea-2026.1"
+    version = "1.0.2-kotlin-2.3.21-RC"
 }
 
 apiValidation {
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 3bb9909e..c3bedc30 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,5 +1,5 @@
 [versions]
-kotlin = "2.3.20"
+kotlin = "2.3.21-RC"
 kotlin-idea = "2.4.0-dev-2631"
 kotlinx-coroutines = "1.10.1"
 kotlinx-binary-compatibility-validator = "0.16.3"