diff --git a/broker/src/main/java/io/moquette/broker/Session.java b/broker/src/main/java/io/moquette/broker/Session.java
index 364722486..38100c712 100644
--- a/broker/src/main/java/io/moquette/broker/Session.java
+++ b/broker/src/main/java/io/moquette/broker/Session.java
@@ -192,6 +192,7 @@ boolean isClean() {
 
     public void processPubRec(int pubRecPacketId) {
         // Message discarded, make sure any buffers in it are released
+        inflightTimeouts.removeIf(d -> d.packetId == pubRecPacketId);
         SessionRegistry.EnqueuedMessage removed = inflightWindow.remove(pubRecPacketId);
         if (removed == null) {
             LOG.warn("Received a PUBREC with not matching packetId");
@@ -218,6 +219,7 @@ public void processPubRec(int pubRecPacketId) {
 
     public void processPubComp(int messageID) {
         // Message discarded, make sure any buffers in it are released
+        inflightTimeouts.removeIf(d -> d.packetId == messageID);
         SessionRegistry.EnqueuedMessage removed = inflightWindow.remove(messageID);
         if (removed == null) {
             LOG.warn("Received a PUBCOMP with not matching packetId");
@@ -343,6 +345,7 @@ private boolean inflightHasSlotsAndConnectionIsUp() {
 
     void pubAckReceived(int ackPacketId) {
         // TODO remain to invoke in somehow m_interceptor.notifyMessageAcknowledged
+        inflightTimeouts.removeIf(d -> d.packetId == ackPacketId);
         SessionRegistry.EnqueuedMessage removed = inflightWindow.remove(ackPacketId);
         if (removed == null) {
             LOG.warn("Received a PUBACK with not matching packetId");
@@ -495,6 +498,7 @@ public void cleanUp() {
         // in case of in memory session queues all contained messages
         // has to be released.
         sessionQueue.closeAndPurge();
+        inflightTimeouts.clear();
         for (EnqueuedMessage msg : inflightWindow.values()) {
             msg.release();
         }