diff --git a/.github/workflows/github-build-release.yml b/.github/workflows/github-build-release.yml
index d6388435..7e26fbfd 100644
--- a/.github/workflows/github-build-release.yml
+++ b/.github/workflows/github-build-release.yml
@@ -11,11 +11,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2
-      - name: Set up JDK 1.8
-        uses: actions/setup-java@v1
+        uses: actions/checkout@v4
+      - name: Set up JDK 11
+        uses: actions/setup-java@v4
         with:
-          java-version: 1.8
+          java-version: '11'
+          distribution: 'temurin'
       - name: Build
         run: mvn package
       - name: Create Release
diff --git a/.github/workflows/java-pr-jobs.yml b/.github/workflows/java-pr-jobs.yml
index c04ab4fb..b4733b20 100644
--- a/.github/workflows/java-pr-jobs.yml
+++ b/.github/workflows/java-pr-jobs.yml
@@ -12,10 +12,11 @@ jobs:
     name: Build and Test
 
     steps:
-      - uses: actions/checkout@v2
-      - name: Set up JDK 1.8
-        uses: actions/setup-java@v1
+      - uses: actions/checkout@v4
+      - name: Set up JDK 11
+        uses: actions/setup-java@v4
         with:
-          java-version: 1.8
+          java-version: '11'
+          distribution: 'temurin'
       - name: Build and test
         run: mvn verify
diff --git a/pom.xml b/pom.xml
index 64b2b00d..dfc93b17 100644
--- a/pom.xml
+++ b/pom.xml
@@ -9,12 +9,12 @@
   <version>1.1.4</version>
 
   <properties>
-    <vertx.version>4.5.15</vertx.version>
+    <vertx.version>5.0.4</vertx.version>
     <logback.version>1.5.11</logback.version>
-    <jackson-databind.version>2.16.1</jackson-databind.version>
-    <junit.version>5.9.2</junit.version>
+    <jackson-databind.version>2.17.0</jackson-databind.version>
+    <junit.version>5.10.2</junit.version>
     <hamcrest.version>2.2</hamcrest.version>
-    <maven.surefire.version>3.0.0-M5</maven.surefire.version>
+    <maven.surefire.version>3.2.5</maven.surefire.version>
   </properties>
   
   <dependencyManagement>
diff --git a/src/main/java/kafka/vertx/demo/Main.java b/src/main/java/kafka/vertx/demo/Main.java
index 0cd467a6..09a72ae3 100644
--- a/src/main/java/kafka/vertx/demo/Main.java
+++ b/src/main/java/kafka/vertx/demo/Main.java
@@ -11,7 +11,6 @@
 import io.vertx.core.*;
 import io.vertx.core.file.FileSystem;
 import io.vertx.core.json.JsonObject;
-import io.vertx.core.spi.resolver.ResolverProvider;
 import org.apache.kafka.common.config.SslConfigs;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -40,7 +39,7 @@ public static void main(String[] args) {
     long startTime = currentTimeMillis();
 
     // Set vertx timeout to deal with slow DNS connections
-    System.setProperty(ResolverProvider.DISABLE_DNS_RESOLVER_PROP_NAME, "true");
+    System.setProperty("vertx.disableDnsResolver", "true");
     Vertx vertx = Vertx.vertx(
       new VertxOptions()
         .setWarningExceptionTime(10).setWarningExceptionTimeUnit(TimeUnit.SECONDS)
@@ -58,7 +57,7 @@ public static void main(String[] args) {
     Future<String> periodicProducerDeployment = vertx.deployVerticle(new PeriodicProducer());
     Future<String> webSocketServerDeployment = vertx.deployVerticle(new WebSocketServer());
 
-    CompositeFuture.join(periodicProducerDeployment, webSocketServerDeployment)
+    Future.all(periodicProducerDeployment, webSocketServerDeployment)
       .onSuccess(ok -> logger.info("✅ Application started in {}ms", currentTimeMillis() - startTime))
       .onFailure(err -> logger.error("❌ Application failed to start", err));
   }
diff --git a/src/main/java/kafka/vertx/demo/WebSocketServer.java b/src/main/java/kafka/vertx/demo/WebSocketServer.java
index 9c02c094..76dd7c57 100644
--- a/src/main/java/kafka/vertx/demo/WebSocketServer.java
+++ b/src/main/java/kafka/vertx/demo/WebSocketServer.java
@@ -75,14 +75,12 @@ private Future<HttpServer> createRouterAndStartServer(JsonObject config) {
 
       data.put("config", props);
 
-      engine.render(data, "webroot/index.html", res -> {
-        if (res.succeeded()) {
-          ctx.response().end(res.result());
-        } else {
-          logger.error(res.cause().getMessage());
-          ctx.fail(res.cause());
-        }
-      });
+      engine.render(data, "webroot/index.html")
+        .onSuccess(buffer -> ctx.response().end(buffer))
+        .onFailure(err -> {
+          logger.error(err.getMessage());
+          ctx.fail(err);
+        });
     });
 
     return startWebSocket(router);
@@ -106,7 +104,7 @@ private void handleWebSocket(ServerWebSocket webSocket) {
         handleConsumeSocket(webSocket);
         break;
       default:
-        webSocket.reject();
+        webSocket.close();
     }
   }
 
diff --git a/src/test/java/kafka/vertx/demo/WebSocketServerTest.java b/src/test/java/kafka/vertx/demo/WebSocketServerTest.java
index b857d8b8..2312be77 100644
--- a/src/test/java/kafka/vertx/demo/WebSocketServerTest.java
+++ b/src/test/java/kafka/vertx/demo/WebSocketServerTest.java
@@ -25,9 +25,8 @@ public class WebSocketServerTest {
 
   @BeforeEach
   void setup(Vertx vertx, VertxTestContext testContext) {
-    vertx.deployVerticle(new WebSocketServer(), res -> {
-      testContext.completeNow();
-    });
+    vertx.deployVerticle(new WebSocketServer())
+      .onComplete(testContext.succeeding(id -> testContext.completeNow()));
   }
 
   @Test
@@ -44,7 +43,8 @@ void getTemplateResponse(Vertx vertx, VertxTestContext testContext) {
 
     client.get(8080, "localhost", "/")
       .as(BodyCodec.string())
-      .send(testContext.succeeding(response -> testContext.verify(() -> {
+      .send()
+      .onComplete(testContext.succeeding(response -> testContext.verify(() -> {
         assertThat(response.body(), CoreMatchers.containsString(EXPECTED));
         testContext.completeNow();
       })));