diff --git a/broker/src/test/java/io/moquette/integration/mqtt5/MessageExpirationTest.java b/broker/src/test/java/io/moquette/integration/mqtt5/MessageExpirationTest.java
index 14ab71198..c65bdde50 100644
--- a/broker/src/test/java/io/moquette/integration/mqtt5/MessageExpirationTest.java
+++ b/broker/src/test/java/io/moquette/integration/mqtt5/MessageExpirationTest.java
@@ -22,12 +22,9 @@
 import com.hivemq.client.mqtt.mqtt5.Mqtt5BlockingClient;
 import com.hivemq.client.mqtt.mqtt5.message.publish.Mqtt5PublishBuilder;
 import com.hivemq.client.mqtt.mqtt5.message.publish.Mqtt5PublishResult;
-import io.netty.handler.codec.mqtt.MqttFixedHeader;
 import io.netty.handler.codec.mqtt.MqttMessage;
-import io.netty.handler.codec.mqtt.MqttMessageIdVariableHeader;
 import io.netty.handler.codec.mqtt.MqttMessageType;
 import io.netty.handler.codec.mqtt.MqttProperties;
-import io.netty.handler.codec.mqtt.MqttPubAckMessage;
 import io.netty.handler.codec.mqtt.MqttPublishMessage;
 import io.netty.handler.codec.mqtt.MqttQoS;
 import org.awaitility.Awaitility;
@@ -43,8 +40,10 @@
 import java.time.Duration;
 import java.util.concurrent.TimeUnit;
 
-import static io.netty.handler.codec.mqtt.MqttQoS.AT_MOST_ONCE;
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class MessageExpirationTest extends AbstractServerIntegrationTest {
     @Override
diff --git a/broker/src/test/java/io/moquette/integration/mqtt5/RequestResponseTest.java b/broker/src/test/java/io/moquette/integration/mqtt5/RequestResponseTest.java
index 1eafab0ad..161a1d3a5 100644
--- a/broker/src/test/java/io/moquette/integration/mqtt5/RequestResponseTest.java
+++ b/broker/src/test/java/io/moquette/integration/mqtt5/RequestResponseTest.java
@@ -26,15 +26,21 @@
 import com.hivemq.client.mqtt.mqtt5.message.subscribe.Mqtt5Subscribe;
 import com.hivemq.client.mqtt.mqtt5.message.subscribe.suback.Mqtt5SubAck;
 import com.hivemq.client.mqtt.mqtt5.message.subscribe.suback.Mqtt5SubAckReasonCode;
+import org.jetbrains.annotations.NotNull;
 import org.junit.jupiter.api.Test;
 
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
 
 public class RequestResponseTest extends AbstractServerIntegrationWithoutClientFixture {
 
@@ -60,7 +66,7 @@ private static void responderRepliesToRequesterPublish(Mqtt5BlockingClient respo
             .topicFilter("requester/door/open")
             .qos(MqttQos.AT_LEAST_ONCE)
             .build();
-        responder.toAsync().subscribe(subscribeToRequest,
+        CompletableFuture<@NotNull Mqtt5SubAck> subackFuture = responder.toAsync().subscribe(subscribeToRequest,
             (Mqtt5Publish pub) -> {
                 assertTrue(pub.getResponseTopic().isPresent(), "Response topic MUST defined in request publish");
                 Mqtt5PublishResult responseResult = responder.publishWith()
@@ -74,6 +80,9 @@ private static void responderRepliesToRequesterPublish(Mqtt5BlockingClient respo
                     "Open door response cannot be published ");
             });
 
+        // wait for the SUBACK in 1 second, else if PUB is sent before the client is fully subscribed, then it's lost
+        waitForSubAck(subackFuture);
+
         Mqtt5PublishResult.Mqtt5Qos1Result requestResult = (Mqtt5PublishResult.Mqtt5Qos1Result) requester.publishWith()
             .topic("requester/door/open")
             .responseTopic(responseTopic)
@@ -104,7 +113,7 @@ public void givenRequestResponseProtocolWhenRequestIsIssueThenTheResponderReplyW
             .topicFilter("requester/door/open")
             .qos(MqttQos.AT_LEAST_ONCE)
             .build();
-        responder.toAsync().subscribe(subscribeToRequest,
+        CompletableFuture<@NotNull Mqtt5SubAck> subackFuture = responder.toAsync().subscribe(subscribeToRequest,
             (Mqtt5Publish pub) -> {
                 assertTrue(pub.getResponseTopic().isPresent(), "Response topic MUST defined in request publish");
                 assertTrue(pub.getCorrelationData().isPresent(), "Correlation data MUST defined in request publish");
@@ -115,6 +124,7 @@ public void givenRequestResponseProtocolWhenRequestIsIssueThenTheResponderReplyW
                     .send();
                 assertFalse(responseResult.getError().isPresent(), "Open door response cannot be published ");
             });
+        waitForSubAck(subackFuture);
 
         Mqtt5PublishResult.Mqtt5Qos1Result requestResult = (Mqtt5PublishResult.Mqtt5Qos1Result) requester.publishWith()
             .topic("requester/door/open")
@@ -136,6 +146,20 @@ public void givenRequestResponseProtocolWhenRequestIsIssueThenTheResponderReplyW
         });
     }
 
+    private static void waitForSubAck(CompletableFuture<@NotNull Mqtt5SubAck> subackFuture) {
+        try {
+            Mqtt5SubAck mqtt5SubAck = subackFuture.get(1, TimeUnit.SECONDS);
+            assertEquals(1, mqtt5SubAck.getReasonCodes().size());
+            assertEquals(Mqtt5SubAckReasonCode.GRANTED_QOS_1, mqtt5SubAck.getReasonCodes().iterator().next());
+        } catch (InterruptedException e) {
+            fail("Sub ack waiting interrupted before 1 sec expires");
+        } catch (ExecutionException e) {
+            throw new RuntimeException(e);
+        } catch (TimeoutException e) {
+            fail("Sub ack didn't arrive in 1 second timeout");
+        }
+    }
+
     private byte[] asByteArray(ByteBuffer byteBuffer) {
         byte[] arr = new byte[byteBuffer.remaining()];
         byteBuffer.get(arr);
diff --git a/broker/src/test/java/io/moquette/testclient/Client.java b/broker/src/test/java/io/moquette/testclient/Client.java
index b406bcf38..e9bba018e 100644
--- a/broker/src/test/java/io/moquette/testclient/Client.java
+++ b/broker/src/test/java/io/moquette/testclient/Client.java
@@ -51,7 +51,7 @@ public interface ICallback {
 
     private static final Logger LOG = LoggerFactory.getLogger(Client.class);
 
-    private static final Duration TIMEOUT_DURATION = Duration.ofMillis(300);
+    private static final Duration TIMEOUT_DURATION = Duration.ofMillis(500);
 
     final ClientNettyMQTTHandler handler = new ClientNettyMQTTHandler();
     EventLoopGroup workerGroup;