diff --git a/.gitignore b/.gitignore
index 293e99e7..6b04aa3e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -45,3 +45,4 @@ broker/nbactions-Server.xml
 
 maven-metadata.xml
 /.gradle/
+/bin/
diff --git a/broker/src/test/java/io/moquette/server/ServerLowlevelMessagesIntegrationTests.java b/broker/src/test/java/io/moquette/server/ServerLowlevelMessagesIntegrationTests.java
index 21975713..00c8a2b8 100644
--- a/broker/src/test/java/io/moquette/server/ServerLowlevelMessagesIntegrationTests.java
+++ b/broker/src/test/java/io/moquette/server/ServerLowlevelMessagesIntegrationTests.java
@@ -97,7 +97,7 @@ public class ServerLowlevelMessagesIntegrationTests {
         MqttConnectVariableHeader mqttConnectVariableHeader = new MqttConnectVariableHeader(
             MqttVersion.MQTT_3_1.protocolName(), MqttVersion.MQTT_3_1.protocolLevel(), false, false, false, 1, false,
             true, keepAlive);
-        MqttConnectPayload mqttConnectPayload = new MqttConnectPayload(clientID, null, null, null, null);
+        MqttConnectPayload mqttConnectPayload = new MqttConnectPayload(clientID, (String)null, (byte[])null, (String)null, (byte[])null);
         return new MqttConnectMessage(mqttFixedHeader, mqttConnectVariableHeader, mqttConnectPayload);
     }
 
diff --git a/broker/src/test/java/io/moquette/testclient/Client.java b/broker/src/test/java/io/moquette/testclient/Client.java
index 6a1ec435..4c9d443e 100644
--- a/broker/src/test/java/io/moquette/testclient/Client.java
+++ b/broker/src/test/java/io/moquette/testclient/Client.java
@@ -109,7 +109,7 @@ public class Client {
         MqttConnectPayload mqttConnectPayload = new MqttConnectPayload(
                 this.clientId,
                 willTestamentTopic,
-                willTestamentMsg,
+                willTestamentMsg.getBytes(),
                 null,
                 null);
         MqttConnectMessage connectMessage = new MqttConnectMessage(
diff --git a/build.gradle b/build.gradle
index 667736b0..ef290c89 100644
--- a/build.gradle
+++ b/build.gradle
@@ -37,7 +37,7 @@ subprojects {
   apply plugin: 'eclipse'
 
   ext {
-    nettyVersion = '4.1.12.Final'
+    nettyVersion = '4.1.22.Final'
   }
 
   task packageTests(type: Jar) {