diff --git a/README.md b/README.md
index cc314b9..7b59668 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 [![CI](https://github.com/rogervinas/wiremock-testing/actions/workflows/gradle.yml/badge.svg?branch=master)](https://github.com/rogervinas/wiremock-testing/actions/workflows/gradle.yml)
 ![Java](https://img.shields.io/badge/Java-21-blue?labelColor=black)
-![Kotlin](https://img.shields.io/badge/Kotlin-1.9.20-blue?labelColor=black)
+![Kotlin](https://img.shields.io/badge/Kotlin-1.9.21-blue?labelColor=black)
 ![WireMock](https://img.shields.io/badge/WireMock-3.3.1-blue?labelColor=black)
 
 # WireMock Testing
diff --git a/build.gradle.kts b/build.gradle.kts
index ec272d9..196dcc2 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -2,7 +2,7 @@ import org.gradle.api.tasks.testing.logging.TestExceptionFormat.FULL
 import org.gradle.api.tasks.testing.logging.TestLogEvent.*
 
 plugins {
-  kotlin("jvm") version "1.9.20"
+  kotlin("jvm") version "1.9.21"
   application
 }