diff --git a/build.gradle b/build.gradle
index 5de38f76..f079d933 100644
--- a/build.gradle
+++ b/build.gradle
@@ -8,7 +8,7 @@ dependencies {
     implementation 'com.auth0:java-jwt:4.5.1'
     implementation 'org.bouncycastle:bcprov-jdk18on:1.84'
 
-    testImplementation 'org.junit.jupiter:junit-jupiter:5.13.1'
+    testImplementation 'org.junit.jupiter:junit-jupiter:6.1.3'
     testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
     testImplementation 'org.mockito:mockito-core:5.23.0'
 }
@@ -28,6 +28,12 @@ tasks.withType(JavaCompile).configureEach {
     options.encoding = 'UTF-8'
 }
 
+// JUnit 6 requires Java 17+
+tasks.named('compileTestJava') {
+    sourceCompatibility = '17'
+    targetCompatibility = '17'
+}
+
 javadoc {
     source = sourceSets.main.allJava
     options.encoding = 'UTF-8'