diff --git a/broker/src/main/java/io/moquette/spi/persistence/MapDBMessagesStore.java b/broker/src/main/java/io/moquette/spi/persistence/MapDBMessagesStore.java
index 8e744dcc..a7d2cf18 100644
--- a/broker/src/main/java/io/moquette/spi/persistence/MapDBMessagesStore.java
+++ b/broker/src/main/java/io/moquette/spi/persistence/MapDBMessagesStore.java
@@ -35,8 +35,6 @@ class MapDBMessagesStore implements IMessagesStore {
 
     private DB m_db;
 
-    //map clientID <-> set of currently in flight packet identifiers
-    private Map<String, Set<Integer>> m_inFlightIds;
     //maps clientID -> guid
     private ConcurrentMap<String, String> m_retainedStore;
     //maps guid to message, it's message store
@@ -51,7 +49,6 @@ class MapDBMessagesStore implements IMessagesStore {
     public void initStore() {
         m_retainedStore = m_db.getHashMap("retained");
         m_persistentMessageStore = m_db.getHashMap("persistedMessages");
-        m_inFlightIds = m_db.getHashMap("inflightPacketIDs");
     }
 
     @Override
@@ -110,27 +107,6 @@ class MapDBMessagesStore implements IMessagesStore {
         return m_persistentMessageStore.get(guid);
     }
 
-//    /**
-//     * Return the next valid packetIdentifier for the given client session.
-//     * */
-//    @Override
-//    public int nextPacketID(String clientID) {
-//        Set<Integer> inFlightForClient = this.m_inFlightIds.get(clientID);
-//        if (inFlightForClient == null) {
-//            int nextPacketId = 1;
-//            inFlightForClient = new HashSet<>();
-//            inFlightForClient.add(nextPacketId);
-//            this.m_inFlightIds.put(clientID, inFlightForClient);
-//            return nextPacketId;
-//
-//        }
-//
-//        int maxId = inFlightForClient.isEmpty() ? 0 : Collections.max(inFlightForClient);
-//        int nextPacketId = (maxId + 1) % 0xFFFF;
-//        inFlightForClient.add(nextPacketId);
-//        return nextPacketId;
-//    }
-
     @Override
     public void cleanRetained(String topic) {
         m_retainedStore.remove(topic);