diff --git a/client.cpp b/client.cpp
index e2889aa..0b845ce 100644
--- a/client.cpp
+++ b/client.cpp
@@ -49,11 +49,11 @@ Client::Client(int fd, std::shared_ptr<ThreadData> threadData, SSL *ssl, bool we
 
 Client::~Client()
 {
+    std::shared_ptr<SubscriptionStore> &store = getThreadData()->getSubscriptionStore();
+
     // Will payload can be empty, apparently.
     if (!will_topic.empty())
     {
-        std::shared_ptr<SubscriptionStore> &store = getThreadData()->getSubscriptionStore();
-
         Publish will(will_topic, will_payload, will_qos);
         will.retain = will_retain;
         const MqttPacket willPacket(will);
@@ -69,6 +69,12 @@ Client::~Client()
     if (epoll_ctl(threadData->epollfd, EPOLL_CTL_DEL, fd, NULL) != 0)
         logger->logf(LOG_ERR, "Removing fd %d of client '%s' from epoll produced error: %s", fd, repr().c_str(), strerror(errno));
     close(fd);
+
+    // MQTT-3.1.2-6
+    if (cleanSession)
+    {
+        store->removeSession(clientid);
+    }
 }
 
 bool Client::isSslAccepted() const
diff --git a/subscriptionstore.cpp b/subscriptionstore.cpp
index cc88461..62a2c31 100644
--- a/subscriptionstore.cpp
+++ b/subscriptionstore.cpp
@@ -492,6 +492,20 @@ int SubscriptionNode::cleanSubscriptions()
     return subscribers.size() + subscribersLeftInChildren;
 }
 
+void SubscriptionStore::removeSession(const std::string &clientid)
+{
+    RWLockGuard lock_guard(&subscriptionsRwlock);
+    lock_guard.wrlock();
+
+    logger->logf(LOG_DEBUG, "Removing session of client '%s'.", clientid.c_str());
+
+    auto session_it = sessionsById.begin();
+    if (session_it != sessionsById.end())
+    {
+        sessionsById.erase(session_it);
+    }
+}
+
 // This is not MQTT compliant, but the standard doesn't keep real world constraints into account.
 void SubscriptionStore::removeExpiredSessionsClients(int expireSessionsAfterSeconds)
 {
diff --git a/subscriptionstore.h b/subscriptionstore.h
index aa5e63f..dec8e57 100644
--- a/subscriptionstore.h
+++ b/subscriptionstore.h
@@ -118,6 +118,7 @@ public:
 
     void setRetainedMessage(const std::string &topic, const std::vector<std::string> &subtopics, const std::string &payload, char qos);
 
+    void removeSession(const std::string &clientid);
     void removeExpiredSessionsClients(int expireSessionsAfterSeconds);
 
     int64_t getRetainedMessageCount() const;