diff --git a/mqtt/hook.go b/mqtt/hook.go
index 7cf9a48..f404549 100644
--- a/mqtt/hook.go
+++ b/mqtt/hook.go
@@ -67,6 +67,7 @@ func (h *MqttServerHook) OnDisconnect(cl *mqttServerV2.Client, err error, expire
 
 	session := GetSession(cl.ID)
 	MqttClientDisconnect(session)
+	DelSession(session.ClientId)
 
 }
 
@@ -106,7 +107,12 @@ func (h *MqttServerHook) OnPublished(cl *mqttServerV2.Client, pk packets.Packet)
 // OnConnectAuthenticate returns true/allowed for all requests.
 func (h *MqttServerHook) OnConnectAuthenticate(cl *mqttServerV2.Client, pk packets.Packet) bool {
 	h.Log.Info("Auth", pk.Connect.Username, pk.Connect.Password)
-	session := CreateSession(cl.ID, pk.Connect.Username, pk.Connect.Password)
+	session := GetSession(cl.ID)
+	if session != nil {
+		MqttClientDisconnect(session)
+		DelSession(session.ClientId)
+	}
+	session = CreateSession(cl.ID, pk.Connect.Username, pk.Connect.Password)
 	err := MqttClientConnect(session)
 	if err != nil {
 		return false
diff --git a/mqtt/session.go b/mqtt/session.go
index b97828e..51e7c6b 100644
--- a/mqtt/session.go
+++ b/mqtt/session.go
@@ -23,3 +23,7 @@ func CreateSession(mqttId string, user, passwd []byte) *Session {
 func GetSession(mqttId string) *Session {
 	return Sessions[mqttId]
 }
+
+func DelSession(mqttId string) {
+	delete(Sessions, mqttId)
+}