diff --git a/src/MQTTAsyncUtils.c b/src/MQTTAsyncUtils.c
index 98507bdf..f0f8ecc5 100644
--- a/src/MQTTAsyncUtils.c
+++ b/src/MQTTAsyncUtils.c
@@ -2262,13 +2262,17 @@ thread_return_type WINAPI MQTTAsync_receiveThread(void* n)
 				else if (pack->header.bits.type == DISCONNECT)
 				{
 					Ack* disc = (Ack*)pack;
+					int discrc = 0;
 
+					discrc = disc->rc;
 					if (m->disconnected)
 					{
 						Log(TRACE_MIN, -1, "Calling disconnected for client %s", m->c->clientID);
 						(*(m->disconnected))(m->disconnected_context, &disc->properties, disc->rc);
 					}
-					MQTTPacket_freeAck(disc);
+					rc = MQTTProtocol_handleDisconnects(pack, m->c->net.socket);
+					m->c->connected = 0; /* don't send disconnect packet back */
+					nextOrClose(m, discrc, "Received disconnect");
 				}
 			}
 		}
diff --git a/src/MQTTPacket.c b/src/MQTTPacket.c
index 296bf31b..6c9a6c5f 100644
--- a/src/MQTTPacket.c
+++ b/src/MQTTPacket.c
@@ -816,10 +816,11 @@ void* MQTTPacket_ack(int MQTTVersion, unsigned char aHeader, char* data, size_t
 		pack->rc = MQTTREASONCODE_SUCCESS;
 		pack->properties = props;
 
-		if (datalen > 2)
+		/* disconnect has no msgid */
+		if (datalen > 2 || (pack->header.bits.type == DISCONNECT && datalen > 0))
 			pack->rc = readChar(&curdata); /* reason code */
 
-		if (datalen > 3)
+		if (datalen > 3 || (pack->header.bits.type == DISCONNECT && datalen > 1))
 		{
 			if (MQTTProperties_read(&pack->properties, &curdata, enddata) != 1)
 			{
diff --git a/src/MQTTProtocolOut.c b/src/MQTTProtocolOut.c
index a3dc787a..733a3392 100644
--- a/src/MQTTProtocolOut.c
+++ b/src/MQTTProtocolOut.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2020 IBM Corp.
+ * Copyright (c) 2009, 2021 IBM Corp., Ian Craggs
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
@@ -443,3 +443,24 @@ int MQTTProtocol_handleUnsubacks(void* pack, int sock)
 	return rc;
 }
 
+
+/**
+ * Process an incoming disconnect packet for a socket
+ * @param pack pointer to the disconnect packet
+ * @param sock the socket on which the packet was received
+ * @return completion code
+ */
+int MQTTProtocol_handleDisconnects(void* pack, int sock)
+{
+	Ack* disconnect = (Ack*)pack;
+	Clients* client = NULL;
+	int rc = TCPSOCKET_COMPLETE;
+
+	FUNC_ENTRY;
+	client = (Clients*)(ListFindItem(bstate->clients, &sock, clientSocketCompare)->content);
+	Log(LOG_PROTOCOL, 30, NULL, sock, client->clientID, disconnect->rc);
+	MQTTPacket_freeAck(disconnect);
+	FUNC_EXIT_RC(rc);
+	return rc;
+}
+
diff --git a/src/MQTTProtocolOut.h b/src/MQTTProtocolOut.h
index a31e2e57..d8f43d73 100644
--- a/src/MQTTProtocolOut.h
+++ b/src/MQTTProtocolOut.h
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2020 IBM Corp.
+ * Copyright (c) 2009, 2021 IBM Corp., Ian Craggs
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
@@ -60,5 +60,6 @@ int MQTTProtocol_subscribe(Clients* client, List* topics, List* qoss, int msgID,
 int MQTTProtocol_handleSubacks(void* pack, int sock);
 int MQTTProtocol_unsubscribe(Clients* client, List* topics, int msgID, MQTTProperties* props);
 int MQTTProtocol_handleUnsubacks(void* pack, int sock);
+int MQTTProtocol_handleDisconnects(void* pack, int sock);
 
 #endif
diff --git a/src/Messages.c b/src/Messages.c
index 299612d9..1b47fadf 100644
--- a/src/Messages.c
+++ b/src/Messages.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2020 IBM Corp.
+ * Copyright (c) 2009, 2021 IBM Corp., Ian Craggs
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
@@ -66,6 +66,7 @@ static const char *protocol_message_list[] =
 	"%d %s -> PUBLISH qos: 0 retained: %d rc: %d payload len(%d): %.*s", /* 27 */
 	"%d %s -> DISCONNECT (%d)", /* 28 */
 	"Socket error for client identifier %s, socket %d, peer address %s; ending connection", /* 29 */
+	"%d %s <- DISCONNECT (%d)", /* 30 */
 };
 
 static const char *trace_message_list[] =