diff --git a/build.gradle b/build.gradle
index 221e716..8fe95c1 100644
--- a/build.gradle
+++ b/build.gradle
@@ -39,16 +39,15 @@ ext {
 
 repositories {
   mavenCentral()
-  jcenter()
 }
 
 dependencies {
   // Compile-time dependencies
 
   // Test dependencies
-  testCompile("org.junit.jupiter:junit-jupiter-api:${junitJupiterVersion}")
-  testCompile("org.assertj:assertj-core:${assertjVersion}")
-  testRuntime("org.junit.jupiter:junit-jupiter-engine:${junitJupiterVersion}")
+  testImplementation("org.junit.jupiter:junit-jupiter-api:${junitJupiterVersion}")
+  testImplementation("org.assertj:assertj-core:${assertjVersion}")
+  testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:${junitJupiterVersion}")
 }
 
 // *********************************************************************************************************************
@@ -63,8 +62,8 @@ eclipse {
 
 idea {
   project {
-    jdkName = '11'
-    languageLevel = '11'
+    jdkName = '21'
+    languageLevel = '21'
   }
 }
 
@@ -85,7 +84,7 @@ test {
 task javadocTests(type: Javadoc, group: "documentation" ) {
   description = 'Generates Javadoc API documentation for the test source code.'
   source = sourceSets.test.allJava
-  classpath = configurations.testCompile
+  classpath = configurations.testCompileClasspath
   options.links(project.ext.javadocLinks)
   options.addBooleanOption('html5',true)
 }
diff --git a/gradle.properties b/gradle.properties
index 11ecfb0..1e82f90 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -3,12 +3,12 @@
 # dependencies. Configuring the properties in this file avoids the need to edit build.gradle except when build logic
 # needs to change.
 # **********************************************************************************************************************
-assertjVersion=3.11.1
+assertjVersion=3.27.7
 description=Java 11 code examples
 group=com.neiljbrown
-junitJupiterVersion=5.3.2
+junitJupiterVersion=5.10.2
 # Set Java source & class versions to use when compiling. Needs to be defined after applying java plugin to take affect
-sourceCompatibility=11
-targetCompatibility=11
+sourceCompatibility=21
+targetCompatibility=21
 # Default project version unless overridden
 version=0.0.1-snapshot
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 75c31a3..bbc9841 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.11-all.zip
diff --git a/pom.xml b/pom.xml
index c1ba53a..7b1a87e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -12,10 +12,10 @@
     <url>https://github.com/neiljbrown/java11-examples</url>
 
     <properties>
-        <java.version>11</java.version>
+        <java.version>21</java.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <junitJupiterVersion>5.3.2</junitJupiterVersion>
-        <assertJVersion>3.11.1</assertJVersion>
+        <junitJupiterVersion>5.10.2</junitJupiterVersion>
+        <assertJVersion>3.27.7</assertJVersion>
     </properties>
 
     <dependencies>
@@ -44,20 +44,19 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.7.0</version>
+                <version>3.11.0</version>
                 <configuration>
-                    <source>${java.version}</source>
-                    <target>${java.version}</target>
+                    <release>${java.version}</release>
                 </configuration>
             </plugin>
             <plugin>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>2.22.0</version>
+                <version>3.2.5</version>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
-                <version>3.0.1</version>
+                <version>3.6.3</version>
                 <configuration>
                     <additionalOptions>-html5</additionalOptions>
                 </configuration>