diff --git a/broker/src/main/java/io/moquette/broker/SessionRegistry.java b/broker/src/main/java/io/moquette/broker/SessionRegistry.java
index 903f9af35..406582da9 100644
--- a/broker/src/main/java/io/moquette/broker/SessionRegistry.java
+++ b/broker/src/main/java/io/moquette/broker/SessionRegistry.java
@@ -26,9 +26,12 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
 import java.net.InetSocketAddress;
 import java.util.Collection;
-import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Queue;
@@ -38,20 +41,44 @@
 
 public class SessionRegistry {
 
-    public abstract static class EnqueuedMessage {
+    public abstract static class EnqueuedMessage implements Serializable {
     }
 
     static class PublishedMessage extends EnqueuedMessage {
 
-        final Topic topic;
-        final MqttQoS publishingQos;
-        final ByteBuf payload;
+        Topic topic;
+        MqttQoS publishingQos;
+        transient ByteBuf payload;
+
+        public PublishedMessage() {
+            this.topic = null;
+            this.publishingQos = null;
+        }
 
         PublishedMessage(Topic topic, MqttQoS publishingQos, ByteBuf payload) {
             this.topic = topic;
             this.publishingQos = publishingQos;
             this.payload = payload;
         }
+
+        private void writeObject(ObjectOutputStream oos) throws IOException {
+            oos.defaultWriteObject();
+            byte[] byteArr = new byte[payload.readableBytes()];
+            ByteBuf copy = payload.copy();
+            copy.readBytes(byteArr);
+            copy.release();
+            oos.writeInt(byteArr.length);
+            oos.write(byteArr);
+        }
+
+        private void readObject(ObjectInputStream ois) throws ClassNotFoundException, IOException {
+            ois.defaultReadObject();
+            int length = ois.readInt();
+            byte[] byteArr = new byte[length];
+            ois.read(byteArr);
+            payload = Unpooled.wrappedBuffer(byteArr);
+        }
+        
     }
 
     static final class PubRelMarker extends EnqueuedMessage {