diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index def983c..7a3640b 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -23,7 +23,7 @@ jobs:
     - name: Set up JDK
       uses: actions/setup-java@v3
       with:
-        java-version: '17'
+        java-version: '21'
         distribution: 'temurin'
     - name: Build with Gradle
       uses: gradle/gradle-build-action@842c587ad8aa4c68eeba24c396e15af4c2e9f30a
diff --git a/README.md b/README.md
index af826ac..52876fa 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 [![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-17-blue?labelColor=black)
+![Java](https://img.shields.io/badge/Java-21-blue?labelColor=black)
 ![Kotlin](https://img.shields.io/badge/Kotlin-1.9.20-blue?labelColor=black)
 ![WireMock](https://img.shields.io/badge/WireMock-3.3.1-blue?labelColor=black)
 
diff --git a/build.gradle.kts b/build.gradle.kts
index 460ebaf..2623137 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -26,7 +26,7 @@ dependencies {
 
 kotlin {
   jvmToolchain {
-    languageVersion.set(JavaLanguageVersion.of(17))
+    languageVersion.set(JavaLanguageVersion.of(21))
   }
 }