diff --git a/httpclient-vertx/src/main/java/io/fabric8/kubernetes/client/vertx/VertxHttpRequest.java b/httpclient-vertx/src/main/java/io/fabric8/kubernetes/client/vertx/VertxHttpRequest.java
index bdff0053a8..1761a738cf 100644
--- a/httpclient-vertx/src/main/java/io/fabric8/kubernetes/client/vertx/VertxHttpRequest.java
+++ b/httpclient-vertx/src/main/java/io/fabric8/kubernetes/client/vertx/VertxHttpRequest.java
@@ -32,6 +32,7 @@
 
 import java.io.InputStream;
 import java.nio.ByteBuffer;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -112,7 +113,7 @@ public void cancel() {
       };
       resp.handler(buffer -> {
         try {
-          consumer.consume(List.of(ByteBuffer.wrap(buffer.getBytes())), result);
+          consumer.consume(Collections.singletonList(ByteBuffer.wrap(buffer.getBytes())), result);
         } catch (Exception e) {
           resp.request().reset();
           result.done().completeExceptionally(e);
diff --git a/httpclient-vertx/src/test/java/io/fabric8/kubernetes/client/vertx/VertxHttpClientBuilderTest.java b/httpclient-vertx/src/test/java/io/fabric8/kubernetes/client/vertx/VertxHttpClientBuilderTest.java
index f42ec8b8b2..b27558602f 100644
--- a/httpclient-vertx/src/test/java/io/fabric8/kubernetes/client/vertx/VertxHttpClientBuilderTest.java
+++ b/httpclient-vertx/src/test/java/io/fabric8/kubernetes/client/vertx/VertxHttpClientBuilderTest.java
@@ -34,7 +34,7 @@ void testZeroTimeouts() {
     HttpClient.Builder builder = factory.newBuilder();
 
     // should build and be usable without an issue
-    try (HttpClient client = builder.connectTimeout(0, TimeUnit.MILLISECONDS).build();) {
+    try (HttpClient client = builder.connectTimeout(0, TimeUnit.MILLISECONDS).build()) {
       assertNotNull(client.newHttpRequestBuilder().uri("http://localhost").build());
     }
   }
@@ -65,7 +65,7 @@ void createsVertxInstanceWhenNoSharedVertx() {
   @Test
   void doesntCloseSharedVertxInstanceWhenClientIsClosed() {
     final Vertx vertx = Vertx.vertx();
-    final var builder = new VertxHttpClientFactory(vertx).newBuilder();
+    final VertxHttpClientBuilder<VertxHttpClientFactory> builder = new VertxHttpClientFactory(vertx).newBuilder();
     builder.build().close();
     assertThat(builder.vertx)
         .asInstanceOf(InstanceOfAssertFactories.type(VertxImpl.class))
@@ -75,7 +75,7 @@ void doesntCloseSharedVertxInstanceWhenClientIsClosed() {
 
   @Test
   void closesVertxInstanceWhenClientIsClosed() {
-    final var builder = new VertxHttpClientFactory().newBuilder();
+    final VertxHttpClientBuilder<VertxHttpClientFactory> builder = new VertxHttpClientFactory().newBuilder();
     builder.build().close();
     assertThat(builder.vertx)
         .asInstanceOf(InstanceOfAssertFactories.type(VertxImpl.class))