diff --git a/MQTTClient-C/src/CMakeLists.txt b/MQTTClient-C/src/CMakeLists.txt
index 632ca4d7..331196a1 100644
--- a/MQTTClient-C/src/CMakeLists.txt
+++ b/MQTTClient-C/src/CMakeLists.txt
@@ -1,5 +1,5 @@
 #*******************************************************************************
-#  Copyright (c) 2017 IBM Corp.
+#  Copyright (c) 2017, 2023 IBM Corp.
 #
 #  All rights reserved. This program and the accompanying materials
 #  are made available under the terms of the Eclipse Public License v1.0
@@ -26,10 +26,12 @@ target_link_libraries(paho-embed-mqtt3cc paho-embed-mqtt3c)
 target_compile_definitions(paho-embed-mqtt3cc PRIVATE
              MQTTCLIENT_PLATFORM_HEADER=MQTTLinux.h MQTTCLIENT_QOS2=1)
 
-file(GLOB SOURCES "*.c" "V5/*.c" "linux/*.c")
-add_library(paho-embed-mqtt5cc SHARED ${SOURCES})
-install(TARGETS paho-embed-mqtt5cc DESTINATION /usr/lib)
-target_include_directories(paho-embed-mqtt5cc PRIVATE "linux")
-target_link_libraries(paho-embed-mqtt5cc paho-embed-mqtt5c)
-target_compile_definitions(paho-embed-mqtt5cc PRIVATE
-             MQTTCLIENT_PLATFORM_HEADER=MQTTLinux.h MQTTCLIENT_QOS2=1 MQTTV5)
+# TODO: Temporarily disable MQTT v5
+#
+# file(GLOB SOURCES "*.c" "V5/*.c" "linux/*.c")
+# add_library(paho-embed-mqtt5cc SHARED ${SOURCES})
+# install(TARGETS paho-embed-mqtt5cc DESTINATION /usr/lib)
+# target_include_directories(paho-embed-mqtt5cc PRIVATE "linux")
+# target_link_libraries(paho-embed-mqtt5cc paho-embed-mqtt5c)
+# target_compile_definitions(paho-embed-mqtt5cc PRIVATE
+#              MQTTCLIENT_PLATFORM_HEADER=MQTTLinux.h MQTTCLIENT_QOS2=1 MQTTV5)
diff --git a/MQTTClient-C/src/MQTTClient.h b/MQTTClient-C/src/MQTTClient.h
index fe9c3c10..47328878 100755
--- a/MQTTClient-C/src/MQTTClient.h
+++ b/MQTTClient-C/src/MQTTClient.h
@@ -35,7 +35,7 @@
 #endif
 
 #if defined(MQTTV5)
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #else
 #include "MQTTPacket.h"
 #endif /* MQTTV5 */
diff --git a/MQTTClient-C/src/V5/MQTTV5Client.h b/MQTTClient-C/src/V5/MQTTV5Client.h
index f87305ff..a32259d5 100755
--- a/MQTTClient-C/src/V5/MQTTV5Client.h
+++ b/MQTTClient-C/src/V5/MQTTV5Client.h
@@ -21,7 +21,7 @@
 
 #include <stdbool.h>
 #include "../MQTTClient.h"
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 
 
 /**
diff --git a/MQTTClient/src/MQTTClient.h b/MQTTClient/src/MQTTClient.h
index a8258f0e..791ae02c 100644
--- a/MQTTClient/src/MQTTClient.h
+++ b/MQTTClient/src/MQTTClient.h
@@ -421,10 +421,16 @@ int MQTT::Client<Network, Timer, a, b>::sendPacket(int32_t length, Timer& timer)
         rc = FAILURE;
 
 #if defined(MQTT_DEBUG)
+
     char printbuf[150];
     DEBUG("Rc %d from sending packet %s\r\n", rc,
+#if defined(MQTTV5)
+        MQTTV5Format_toServerString(printbuf, sizeof(printbuf), sendbuf, length));
+#else
         MQTTFormat_toServerString(printbuf, sizeof(printbuf), sendbuf, length));
-#endif
+#endif // MQTTV5
+
+#endif // MQTT_DEBUG
     return rc;
 }
 
@@ -503,7 +509,12 @@ int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::readPacket(Timer& tim
     {
         char printbuf[50];
         DEBUG("Rc %d receiving packet %s\r\n", rc,
-            MQTTFormat_toClientString(printbuf, sizeof(printbuf), readbuf, len));
+#if defined(MQTTV5)
+        MQTTV5Format_toClientString(printbuf, sizeof(printbuf), readbuf, len));
+#else
+        MQTTFormat_toClientString(printbuf, sizeof(printbuf), readbuf, len));
+#endif // MQTTV5
+
     }
 #endif
     return rc;
diff --git a/MQTTPacket/samples/v5log.c b/MQTTPacket/samples/v5log.c
index 260c62c5..a0fa723a 100644
--- a/MQTTPacket/samples/v5log.c
+++ b/MQTTPacket/samples/v5log.c
@@ -12,7 +12,8 @@
  *
  *******************************************************************************/
 
-#include "V5/MQTTV5Packet.h"
+#include <stdio.h>
+#include "MQTTV5Packet.h"
 
 static const char* v5property_identifier_to_string(int identifier)
 {
diff --git a/MQTTPacket/samples/v5log.h b/MQTTPacket/samples/v5log.h
index 300a041c..c8c8fa11 100644
--- a/MQTTPacket/samples/v5log.h
+++ b/MQTTPacket/samples/v5log.h
@@ -12,7 +12,7 @@
  *
  *******************************************************************************/
 
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 
 void v5property_print(MQTTProperty property);
 const char* v5reasoncode_to_string(int reasoncode);
diff --git a/MQTTPacket/samples/v5ping.c b/MQTTPacket/samples/v5ping.c
index 21be61c9..60de103a 100644
--- a/MQTTPacket/samples/v5ping.c
+++ b/MQTTPacket/samples/v5ping.c
@@ -16,7 +16,7 @@
 #include <string.h>
 #include <stdlib.h>
 
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #include "transport.h"
 #include "v5log.h"
 
@@ -92,15 +92,14 @@ int main(int argc, char *argv[])
 
 	data.clientID.cstring = "paho-emb-ping";
 	data.keepAliveInterval = KEEPALIVE_INTERVAL;
-	data.cleansession = 1;
+	data.cleanstart = 1;
 	data.username.cstring = "rw";
 	data.password.cstring = "readwrite";
 	data.MQTTVersion = 5;
 
 	MQTTProperties conn_properties = MQTTProperties_initializer;
-	MQTTProperties will_properties = MQTTProperties_initializer;
 
-	len = MQTTV5Serialize_connect(buf, buflen, &data, &conn_properties, &will_properties);
+	len = MQTTV5Serialize_connect(buf, buflen, &data, &conn_properties);
 	rc = transport_sendPacketBuffer(mysock, buf, len);
 
 	printf("Sent MQTTv5 connect\n");
diff --git a/MQTTPacket/samples/v5ping_nb.c b/MQTTPacket/samples/v5ping_nb.c
index cc5b6837..2889fce5 100644
--- a/MQTTPacket/samples/v5ping_nb.c
+++ b/MQTTPacket/samples/v5ping_nb.c
@@ -16,7 +16,7 @@
 #include <string.h>
 #include <stdlib.h>
 
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #include "transport.h"
 #include "v5log.h"
 
@@ -99,15 +99,14 @@ int main(int argc, char *argv[])
 	mytransport.state = 0;
 	data.clientID.cstring = "paho-emb-ping_nb";
 	data.keepAliveInterval = KEEPALIVE_INTERVAL;
-	data.cleansession = 1;
+	data.cleanstart = 1;
 	data.username.cstring = "rw";
 	data.password.cstring = "readwrite";
 	data.MQTTVersion = 5;
 
 	MQTTProperties conn_properties = MQTTProperties_initializer;
-	MQTTProperties will_properties = MQTTProperties_initializer;
 
-	len = MQTTV5Serialize_connect(buf, buflen, &data, &conn_properties, &will_properties);
+	len = MQTTV5Serialize_connect(buf, buflen, &data, &conn_properties);
 	rc = transport_sendPacketBuffer(mysock, buf, len);
 
 	printf("Sent MQTT connect\n");
diff --git a/MQTTPacket/samples/v5pub0sub1.c b/MQTTPacket/samples/v5pub0sub1.c
index 95555d1c..3df9b4ea 100644
--- a/MQTTPacket/samples/v5pub0sub1.c
+++ b/MQTTPacket/samples/v5pub0sub1.c
@@ -16,7 +16,7 @@
 #include <string.h>
 #include <stdlib.h>
 
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #include "transport.h"
 #include "v5log.h"
 
@@ -80,15 +80,14 @@ int main(int argc, char *argv[])
 
 	data.clientID.cstring = "paho-emb-v5pub0sub1";
 	data.keepAliveInterval = 20;
-	data.cleansession = 1;
+	data.cleanstart = 1;
 	data.username.cstring = "rw";
 	data.password.cstring = "readwrite";
 	data.MQTTVersion = 5;
 
 	MQTTProperties conn_properties = MQTTProperties_initializer;
-	MQTTProperties will_properties = MQTTProperties_initializer;
 
-	len = MQTTV5Serialize_connect(buf, buflen, &data, &conn_properties, &will_properties);
+	len = MQTTV5Serialize_connect(buf, buflen, &data, &conn_properties);
 	rc = transport_sendPacketBuffer(mysock, buf, len);
 
 	/* wait for connack */
@@ -259,7 +258,7 @@ int main(int argc, char *argv[])
 	}
 
 	printf("disconnecting\n");
-	len = MQTTSerialize_disconnect(buf, buflen);
+	len = MQTTV5Serialize_disconnect(buf, buflen, MQTTREASONCODE_NORMAL_DISCONNECTION, NULL);
 	rc = transport_sendPacketBuffer(mysock, buf, len);
 
 exit:
diff --git a/MQTTPacket/samples/v5pub0sub1_nb.c b/MQTTPacket/samples/v5pub0sub1_nb.c
index 92213790..6528fd4c 100644
--- a/MQTTPacket/samples/v5pub0sub1_nb.c
+++ b/MQTTPacket/samples/v5pub0sub1_nb.c
@@ -90,9 +90,8 @@ int main(int argc, char *argv[])
 	data.MQTTVersion = 5;
 
 	MQTTProperties conn_properties = MQTTProperties_initializer;
-	MQTTProperties will_properties = MQTTProperties_initializer;
 
-	len = MQTTV5Serialize_connect(buf, buflen, &data, &conn_properties, &will_properties);
+	len = MQTTV5Serialize_connect(buf, buflen, &data, &conn_properties);
 	rc = transport_sendPacketBuffer(mysock, buf, len);
 
 	/* wait for connack */
@@ -272,7 +271,7 @@ int main(int argc, char *argv[])
 	}
 
 	printf("disconnecting\n");
-	len = MQTTSerialize_disconnect(buf, buflen);
+	len = MQTTV5Serialize_disconnect(buf, buflen, MQTTREASONCODE_NORMAL_DISCONNECTION, NULL);
 	rc = transport_sendPacketBuffer(mysock, buf, len);
 
 exit:
diff --git a/MQTTPacket/samples/v5qos0pub.c b/MQTTPacket/samples/v5qos0pub.c
index a66ff8c0..fd0d703f 100644
--- a/MQTTPacket/samples/v5qos0pub.c
+++ b/MQTTPacket/samples/v5qos0pub.c
@@ -16,7 +16,7 @@
 #include <string.h>
 #include <stdlib.h>
 
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #include "transport.h"
 #include "v5log.h"
 
@@ -48,15 +48,13 @@ int main(int argc, char *argv[])
 
 	conn_data.clientID.cstring = "paho-emb-v5qos0pub";
 	conn_data.keepAliveInterval = 20;
-	conn_data.cleansession = 1;
+	conn_data.cleanstart = 1;
 	conn_data.username.cstring = "rw";
 	conn_data.password.cstring = "readwrite";
 	conn_data.MQTTVersion = 5;
 
 	MQTTProperties conn_properties = MQTTProperties_initializer;
-	MQTTProperties will_properties = MQTTProperties_initializer;
-	
-	len = MQTTV5Serialize_connect((unsigned char *)buf, buflen, &conn_data, &conn_properties, &will_properties);
+	len = MQTTV5Serialize_connect((unsigned char *)buf, buflen, &conn_data, &conn_properties);
 
 	MQTTProperty pub_properties_array[1];
 	MQTTProperties pub_properties = MQTTProperties_initializer;
diff --git a/MQTTPacket/src/CMakeLists.txt b/MQTTPacket/src/CMakeLists.txt
index e4054481..41c87fa2 100644
--- a/MQTTPacket/src/CMakeLists.txt
+++ b/MQTTPacket/src/CMakeLists.txt
@@ -1,5 +1,5 @@
 #*******************************************************************************
-#  Copyright (c) 2017 IBM Corp.
+#  Copyright (c) 2017, 2023 IBM Corp.
 #
 #  All rights reserved. This program and the accompanying materials
 #  are made available under the terms of the Eclipse Public License v1.0
@@ -15,33 +15,33 @@
 #*******************************************************************************/
 
 # MQTTPacket Library
-file(GLOB SOURCES "*.c")
+file(GLOB SOURCES "*.c" "V3/*.c")
 add_library(paho-embed-mqtt3c SHARED ${SOURCES})
 install(TARGETS paho-embed-mqtt3c DESTINATION /usr/lib)
 target_compile_definitions(paho-embed-mqtt3c PRIVATE MQTT_SERVER MQTT_CLIENT)
 
-add_library(MQTTPacketClient SHARED MQTTFormat MQTTPacket
+add_library(MQTTPacketClient SHARED V3/MQTTFormat MQTTPacket
             MQTTSerializePublish MQTTDeserializePublish
             MQTTConnectClient MQTTSubscribeClient MQTTUnsubscribeClient)
 target_compile_definitions(MQTTPacketClient PRIVATE MQTT_CLIENT)
 
-add_library(MQTTPacketServer SHARED MQTTFormat MQTTPacket
+add_library(MQTTPacketServer SHARED V3/MQTTFormat MQTTPacket
             MQTTSerializePublish MQTTDeserializePublish
             MQTTConnectServer MQTTSubscribeServer MQTTUnsubscribeServer)
 target_compile_definitions(MQTTPacketServer PRIVATE MQTT_SERVER)
 
-file(GLOB SOURCES5 "*.c" "V5/*.c" ../samples/transport.c)
+file(GLOB SOURCES5 "*.c" "V5/*.c")
 
 add_library(paho-embed-mqtt5c SHARED ${SOURCES5})
 install(TARGETS paho-embed-mqtt5c DESTINATION /usr/lib)
 target_compile_definitions(paho-embed-mqtt5c PRIVATE MQTT_SERVER MQTT_CLIENT MQTTV5)
 
-add_library(MQTTPacketClient5 SHARED MQTTFormat MQTTPacket
+add_library(MQTTPacketClient5 SHARED V5/MQTTV5Format MQTTPacket
             MQTTSerializePublish MQTTDeserializePublish V5/MQTTProperties V5/MQTTV5Packet
             MQTTConnectClient MQTTSubscribeClient MQTTUnsubscribeClient)
 target_compile_definitions(MQTTPacketClient5 PRIVATE MQTT_CLIENT MQTTV5)
 
-add_library(MQTTPacketServer5 SHARED MQTTFormat MQTTPacket
+add_library(MQTTPacketServer5 SHARED V5/MQTTV5Format MQTTPacket
             MQTTSerializePublish MQTTDeserializePublish V5/MQTTProperties V5/MQTTV5Packet
             MQTTConnectServer MQTTSubscribeServer MQTTUnsubscribeServer)
 target_compile_definitions(MQTTPacketServer5 PRIVATE MQTT_SERVER MQTTV5)
diff --git a/MQTTPacket/src/MQTTConnectClient.c b/MQTTPacket/src/MQTTConnectClient.c
index d46eaf8d..c7a2b0d9 100644
--- a/MQTTPacket/src/MQTTConnectClient.c
+++ b/MQTTPacket/src/MQTTConnectClient.c
@@ -15,7 +15,7 @@
  *******************************************************************************/
 
 #if defined(MQTTV5)
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #else
 #include "MQTTPacket.h"
 #endif
@@ -29,8 +29,7 @@
   * @return the length of buffer needed to contain the serialized version of the packet
   */
 #if defined(MQTTV5)
-int MQTTSerialize_connectLength(MQTTPacket_connectData* options, MQTTProperties* connectProperties,
-  MQTTProperties* willProperties)
+int MQTTSerialize_connectLength(MQTTPacket_connectData* options, MQTTProperties* connectProperties)
 #else
 int MQTTSerialize_connectLength(MQTTPacket_connectData* options)
 #endif
@@ -56,8 +55,8 @@ int MQTTSerialize_connectLength(MQTTPacket_connectData* options)
 	{
     if (connectProperties)
 	    len += MQTTProperties_len(connectProperties);
-	  if (options->willFlag && willProperties)
-		  len += MQTTProperties_len(willProperties);
+	  if (options->willFlag && options->will.properties)
+		  len += MQTTProperties_len(options->will.properties);
 	}
 #endif
 
@@ -65,7 +64,6 @@ int MQTTSerialize_connectLength(MQTTPacket_connectData* options)
 	return len;
 }
 
-
 /**
   * Serializes the connect options into the buffer.
   * @param buf the buffer into which the packet will be serialized
@@ -74,13 +72,8 @@ int MQTTSerialize_connectLength(MQTTPacket_connectData* options)
   * @return serialized length, or error if 0
   */
 #if defined(MQTTV5)
-int MQTTSerialize_connect(unsigned char* buf, int32_t buflen, MQTTPacket_connectData* options)
-{
-  return MQTTV5Serialize_connect(buf, buflen, options, NULL, NULL);
-}
-
 int MQTTV5Serialize_connect(unsigned char* buf, int32_t buflen, MQTTPacket_connectData* options,
-  MQTTProperties* connectProperties, MQTTProperties* willProperties)
+  MQTTProperties* connectProperties)
 #else
 int MQTTSerialize_connect(unsigned char* buf, int32_t buflen, MQTTPacket_connectData* options)
 #endif
@@ -93,8 +86,7 @@ int MQTTSerialize_connect(unsigned char* buf, int32_t buflen, MQTTPacket_connect
 
 	FUNC_ENTRY;
 	#if defined(MQTTV5)
-	if (MQTTPacket_len(len = MQTTSerialize_connectLength(options,
-		         connectProperties, willProperties)) > buflen)
+	if (MQTTPacket_len(len = MQTTSerialize_connectLength(options, connectProperties)) > buflen)
 	#else
 	if (MQTTPacket_len(len = MQTTSerialize_connectLength(options)) > buflen)
 	#endif
@@ -147,8 +139,8 @@ int MQTTSerialize_connect(unsigned char* buf, int32_t buflen, MQTTPacket_connect
 	{
 #if defined(MQTTV5)
 		/* write will properties */
-		if (options->MQTTVersion == 5 && willProperties)
-		  MQTTProperties_write(&ptr, willProperties);
+		if (options->MQTTVersion == 5 && options->will.properties)
+		  MQTTProperties_write(&ptr, options->will.properties);
 #endif
 		writeMQTTString(&ptr, options->will.topicName);
 		writeMQTTString(&ptr, options->will.message);
@@ -174,11 +166,6 @@ int MQTTSerialize_connect(unsigned char* buf, int32_t buflen, MQTTPacket_connect
   * @return error code.  1 is success, 0 is failure
   */
 #if defined(MQTTV5)
-int MQTTDeserialize_connack(unsigned char* sessionPresent, unsigned char* connack_rc, unsigned char* buf, int32_t buflen)
-{
-	return MQTTV5Deserialize_connack(NULL, sessionPresent, connack_rc, buf, buflen);
-}
-
 int MQTTV5Deserialize_connack(MQTTProperties* connackProperties, unsigned char* sessionPresent, unsigned char* connack_rc,
 	unsigned char* buf, int32_t buflen)
 #else
@@ -229,11 +216,6 @@ int MQTTDeserialize_connack(unsigned char* sessionPresent, unsigned char* connac
 int MQTTV5Serialize_zero(unsigned char* buf, int32_t buflen, unsigned char packettype,
  unsigned char reasonCode, MQTTProperties* properties);
 
-int MQTTSerialize_zero(unsigned char* buf, int32_t buflen, unsigned char packettype)
-{
-	return MQTTV5Serialize_zero(buf, buflen, packettype, -1, NULL);
-}
-
 int MQTTV5Serialize_zero(unsigned char* buf, int32_t buflen, unsigned char packettype,
  unsigned char reasonCode, MQTTProperties* properties)
 #else
@@ -286,11 +268,6 @@ int MQTTSerialize_zero(unsigned char* buf, int32_t buflen, unsigned char packett
   * @return serialized length, or error if 0
   */
 #if defined(MQTTV5)
-int MQTTSerialize_disconnect(unsigned char* buf, int32_t buflen)
-{
-  return MQTTV5Serialize_disconnect(buf, buflen, -1, NULL);
-}
-
 int MQTTV5Serialize_disconnect(unsigned char* buf, int32_t buflen,
 	            unsigned char reasonCode, MQTTProperties* properties)
 #else
@@ -322,5 +299,9 @@ int MQTTV5Serialize_auth(unsigned char* buf, int32_t buflen,
   */
 int MQTTSerialize_pingreq(unsigned char* buf, int32_t buflen)
 {
+#if defined(MQTTV5)
+	return MQTTV5Serialize_zero(buf, buflen, PINGREQ, -1, NULL);
+#else
 	return MQTTSerialize_zero(buf, buflen, PINGREQ);
+#endif
 }
diff --git a/MQTTPacket/src/MQTTConnect.h b/MQTTPacket/src/MQTTConnectCommon.h
similarity index 73%
rename from MQTTPacket/src/MQTTConnect.h
rename to MQTTPacket/src/MQTTConnectCommon.h
index 27d92512..6c8d3e24 100644
--- a/MQTTPacket/src/MQTTConnect.h
+++ b/MQTTPacket/src/MQTTConnectCommon.h
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2014, 2023 IBM Corp. and others
+ * Copyright (c) 2023 Microsoft Corporation. All rights reserved.
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -10,18 +10,15 @@
  * and the Eclipse Distribution License is available at
  *   http://www.eclipse.org/org/documents/edl-v10.php.
  *
- * Contributors:
- *    Ian Craggs - initial API and implementation and/or initial documentation
- *    Ian Craggs - add connack return code definitions
- *    Xiang Rong - 442039 Add makefile to Embedded C client
- *    Ian Craggs - fix for issue #64, bit order in connack response
  *******************************************************************************/
 
-#ifndef MQTTCONNECT_H_
-#define MQTTCONNECT_H_
+#ifndef MQTTCONNECT_COMMON_H_
+#define MQTTCONNECT_COMMON_H_
 
 #include <stdint.h>
-
+#if defined(MQTTV5)
+#include "V5/MQTTProperties.h"
+#else
 enum MQTTConnackReturnCodes
 {
     MQTTCONNACK_CONNECTION_ACCEPTED = 0,
@@ -31,6 +28,8 @@ enum MQTTConnackReturnCodes
     MQTTCONNACK_BAD_USERNAME_OR_PASSWORD = 4,
     MQTTCONNACK_NOT_AUTHORIZED = 5,
 };
+#endif
+
 
 #if !defined(DLLImport)
   #define DLLImport
@@ -78,8 +77,6 @@ typedef struct
 {
 	/** The eyecatcher for this structure.  must be MQTW. */
 	char struct_id[4];
-	/** The version number of this structure.  Must be 0 */
-	int struct_version;
 	/** The LWT topic to which the LWT message will be published. */
 	MQTTString topicName;
 	/** The LWT payload. */
@@ -93,19 +90,25 @@ typedef struct
       * MQTTAsync_message.qos and @ref qos).
       */
 	char qos;
+#if defined(MQTTV5)
+	/**
+	  * LWT properties.
+	  */
+	MQTTProperties* properties;
+#endif
 } MQTTPacket_willOptions;
 
-
-#define MQTTPacket_willOptions_initializer { {'M', 'Q', 'T', 'W'}, 0, {NULL, {0, NULL}}, {NULL, {0, NULL}}, 0, 0 }
-
+#if defined(MQTTV5)
+#define MQTTPacket_willOptions_initializer { {'M', 'Q', 'T', 'W'}, {NULL, {0, NULL}}, {NULL, {0, NULL}}, 0, 0, NULL }
+#else
+#define MQTTPacket_willOptions_initializer { {'M', 'Q', 'T', 'W'}, {NULL, {0, NULL}}, {NULL, {0, NULL}}, 0, 0 }
+#endif
 
 typedef struct
 {
 	/** The eyecatcher for this structure.  must be MQTC. */
 	char struct_id[4];
-	/** The version number of this structure.  Must be 0 */
-	int struct_version;
-	/** Version of MQTT to be used.  3 = 3.1 4 = 3.1.1
+	/** Version of MQTT to be used.  3 = 3.1 4 = 3.1.1, 5 = 5.0
 	  */
 	unsigned char MQTTVersion;
 	MQTTString clientID;
@@ -139,17 +142,14 @@ typedef union
 #endif
 } MQTTConnackFlags;	/**< connack flags byte */
 
-#define MQTTPacket_connectData_initializer { {'M', 'Q', 'T', 'C'}, 0, 4, {NULL, {0, NULL}}, 60, 1, 0, \
+#if defined(MQTTV5)
+#define MQTTPacket_connectData_initializer { {'M', 'Q', 'T', 'C'}, 5, {NULL, {0, NULL}}, 60, 1, 0, \
 		MQTTPacket_willOptions_initializer, {NULL, {0, NULL}}, {NULL, {0, NULL}} }
+#else
+#define MQTTPacket_connectData_initializer { {'M', 'Q', 'T', 'C'}, 4, {NULL, {0, NULL}}, 60, 1, 0, \
+		MQTTPacket_willOptions_initializer, {NULL, {0, NULL}}, {NULL, {0, NULL}} }
+#endif
 
-DLLExport int MQTTSerialize_connect(unsigned char* buf, int32_t buflen, MQTTPacket_connectData* options);
-DLLExport int MQTTDeserialize_connect(MQTTPacket_connectData* data, unsigned char* buf, int32_t len);
-
-DLLExport int MQTTSerialize_connack(unsigned char* buf, int32_t buflen, unsigned char connack_rc, unsigned char sessionPresent);
-DLLExport int MQTTDeserialize_connack(unsigned char* sessionPresent, unsigned char* connack_rc, unsigned char* buf, int32_t buflen);
-
-DLLExport int MQTTSerialize_disconnect(unsigned char* buf, int32_t buflen);
-DLLExport int MQTTDeserialize_disconnect(unsigned char* buf, int32_t buflen);
 DLLExport int MQTTSerialize_pingreq(unsigned char* buf, int32_t buflen);
 
-#endif /* MQTTCONNECT_H_ */
+#endif /* MQTTCONNECT_COMMON_H_ */
diff --git a/MQTTPacket/src/MQTTConnectServer.c b/MQTTPacket/src/MQTTConnectServer.c
index 842e94fa..46abba4c 100644
--- a/MQTTPacket/src/MQTTConnectServer.c
+++ b/MQTTPacket/src/MQTTConnectServer.c
@@ -17,7 +17,7 @@
 
 #include "StackTrace.h"
 #if defined(MQTTV5)
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #else
 #include "MQTTPacket.h"
 #endif
@@ -55,7 +55,7 @@ int MQTTPacket_checkVersion(MQTTString* protocol, int version)
 #if defined(MQTTV5)
 int32_t MQTTDeserialize_connect(MQTTPacket_connectData* data, unsigned char* buf, int32_t len)
 {
-	return MQTTV5Deserialize_connect(NULL, NULL, data, buf, len);
+	return MQTTV5Deserialize_connect(NULL, data, buf, len);
 }
 
 /**
@@ -67,8 +67,8 @@ int32_t MQTTDeserialize_connect(MQTTPacket_connectData* data, unsigned char* buf
   * @param len the length in bytes of the data in the supplied buffer
   * @return error code.  1 is success, 0 is failure
   */
-int32_t MQTTV5Deserialize_connect(MQTTProperties* willProperties, MQTTProperties* connectProperties,
-	MQTTPacket_connectData* data, unsigned char* buf, int32_t len)
+int32_t MQTTV5Deserialize_connect(MQTTProperties* connectProperties, MQTTPacket_connectData* data, 
+	unsigned char* buf, int32_t len)
 #else
 /**
   * Deserializes the supplied (wire) buffer into connect data structure
@@ -128,7 +128,7 @@ int32_t MQTTDeserialize_connect(MQTTPacket_connectData* data, unsigned char* buf
 			#if defined(MQTTV5)
 			if (data->MQTTVersion == 5)
 			{
-				if (!MQTTProperties_read(willProperties, &curdata, enddata))
+				if (!MQTTProperties_read(data->will.properties, &curdata, enddata))
 				  goto exit;
 			}
 			#endif
diff --git a/MQTTPacket/src/MQTTDeserializePublish.c b/MQTTPacket/src/MQTTDeserializePublish.c
index bc695470..1e19e229 100644
--- a/MQTTPacket/src/MQTTDeserializePublish.c
+++ b/MQTTPacket/src/MQTTDeserializePublish.c
@@ -16,7 +16,7 @@
  *******************************************************************************/
 
 #if defined(MQTTV5)
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #else
 #include "MQTTPacket.h"
 #endif
diff --git a/MQTTPacket/src/MQTTPacket.c b/MQTTPacket/src/MQTTPacket.c
index 68770de3..e9715e89 100644
--- a/MQTTPacket/src/MQTTPacket.c
+++ b/MQTTPacket/src/MQTTPacket.c
@@ -16,7 +16,12 @@
  *******************************************************************************/
 
 #include "StackTrace.h"
+
+#if defined(MQTTV5)
+#include "MQTTV5Packet.h"
+#else
 #include "MQTTPacket.h"
+#endif
 
 #include <string.h>
 
diff --git a/MQTTPacket/src/MQTTPacket.h b/MQTTPacket/src/MQTTPacket.h
index 13860697..5b2d7239 100644
--- a/MQTTPacket/src/MQTTPacket.h
+++ b/MQTTPacket/src/MQTTPacket.h
@@ -24,112 +24,12 @@
 extern "C" {
 #endif
 
-#if defined(WIN32_DLL) || defined(WIN64_DLL)
-  #define DLLImport __declspec(dllimport)
-  #define DLLExport __declspec(dllexport)
-#elif defined(LINUX_SO)
-  #define DLLImport extern
-  #define DLLExport  __attribute__ ((visibility ("default")))
-#else
-  #define DLLImport
-  #define DLLExport
-#endif
-
-enum errors
-{
-	MQTTPACKET_BUFFER_TOO_SHORT = -2,
-	MQTTPACKET_READ_ERROR = -1,
-	MQTTPACKET_READ_COMPLETE
-};
-
-enum msgTypes
-{
-	CONNECT = 1, CONNACK, PUBLISH, PUBACK, PUBREC, PUBREL,
-	PUBCOMP, SUBSCRIBE, SUBACK, UNSUBSCRIBE, UNSUBACK,
-	PINGREQ, PINGRESP, DISCONNECT
-#if defined(MQTTV5)
-  , AUTH
-#endif /* MQTTV5 */
-};
-
-/**
- * Bitfields for the MQTT header byte.
- */
-typedef union
-{
-	unsigned char byte;	                /**< the whole byte */
-#if defined(REVERSED)
-	struct
-	{
-		unsigned int type : 4;			/**< message type nibble */
-		unsigned int dup : 1;				/**< DUP flag bit */
-		unsigned int qos : 2;				/**< QoS value, 0, 1 or 2 */
-		unsigned int retain : 1;		/**< retained flag bit */
-	} bits;
-#else
-	struct
-	{
-		unsigned int retain : 1;		/**< retained flag bit */
-		unsigned int qos : 2;				/**< QoS value, 0, 1 or 2 */
-		unsigned int dup : 1;				/**< DUP flag bit */
-		unsigned int type : 4;			/**< message type nibble */
-	} bits;
-#endif
-} MQTTHeader;
-
-typedef struct
-{
-	int32_t len;
-	char* data;
-} MQTTLenString;
-
-typedef struct
-{
-	char* cstring;
-	MQTTLenString lenstring;
-} MQTTString;
-
-#define MQTTString_initializer {NULL, {0, NULL}}
-
-int MQTTstrlen(MQTTString mqttstring);
-
-#include "MQTTConnect.h"
-#include "MQTTPublish.h"
-#include "MQTTSubscribe.h"
-#include "MQTTUnsubscribe.h"
-#include "MQTTFormat.h"
-
-DLLExport int32_t MQTTSerialize_ack(unsigned char* buf, int32_t buflen, unsigned char type, unsigned char dup, unsigned short packetid);
-DLLExport int32_t MQTTDeserialize_ack(unsigned char* packettype, unsigned char* dup, unsigned short* packetid, unsigned char* buf, int32_t buflen);
-
-int32_t MQTTPacket_VBIlen(int32_t rem_len);
-int32_t MQTTPacket_len(int32_t rem_len);
-DLLExport int MQTTPacket_equals(MQTTString* a, char* b);
-
-DLLExport int32_t MQTTPacket_encode(unsigned char* buf, int32_t length);
-int32_t MQTTPacket_decode(int (*getcharfn)(unsigned char*, int), int32_t* value);
-int32_t MQTTPacket_decodeBuf(unsigned char* buf, int32_t* value);
-
-int readInt(unsigned char** pptr);
-char readChar(unsigned char** pptr);
-void writeChar(unsigned char** pptr, char c);
-void writeInt(unsigned char** pptr, int anInt);
-int readMQTTLenString(MQTTString* mqttstring, unsigned char** pptr, unsigned char* enddata);
-void writeCString(unsigned char** pptr, const char* string);
-void writeMQTTString(unsigned char** pptr, MQTTString mqttstring);
-
-DLLExport int MQTTPacket_read(unsigned char* buf, int32_t buflen, int (*getfn)(unsigned char*, int));
-
-typedef struct {
-	int (*getfn)(void *, unsigned char*, int); /* must return -1 for error, 0 for call again, or the number of bytes read */
-	void *sck;	/* pointer to whatever the system may use to identify the transport */
-	int multiplier;
-	int rem_len;
-	int32_t len;
-	char state;
-}MQTTTransport;
-
-int MQTTPacket_readnb(unsigned char* buf, int32_t buflen, MQTTTransport *trp);
+#include "MQTTPacketCommon.h"
+#include "V3/MQTTConnect.h"
+#include "V3/MQTTPublish.h"
+#include "V3/MQTTSubscribe.h"
+#include "V3/MQTTUnsubscribe.h"
+#include "V3/MQTTFormat.h"
 
 #ifdef __cplusplus /* If this is a C++ compiler, use C linkage */
 }
diff --git a/MQTTPacket/src/MQTTPacketCommon.h b/MQTTPacket/src/MQTTPacketCommon.h
new file mode 100644
index 00000000..1eb7ee8e
--- /dev/null
+++ b/MQTTPacket/src/MQTTPacketCommon.h
@@ -0,0 +1,130 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Microsoft Corporation. All rights reserved.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ *
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *   http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ *******************************************************************************/
+
+#ifndef MQTTPACKETCOMMON_H_
+#define MQTTPACKETCOMMON_H_
+
+#include <stdint.h>
+
+#if defined(__cplusplus) /* If this is a C++ compiler, use C linkage */
+extern "C" {
+#endif
+
+#if defined(WIN32_DLL) || defined(WIN64_DLL)
+  #define DLLImport __declspec(dllimport)
+  #define DLLExport __declspec(dllexport)
+#elif defined(LINUX_SO)
+  #define DLLImport extern
+  #define DLLExport  __attribute__ ((visibility ("default")))
+#else
+  #define DLLImport
+  #define DLLExport
+#endif
+
+enum errors
+{
+	MQTTPACKET_BUFFER_TOO_SHORT = -2,
+	MQTTPACKET_READ_ERROR = -1,
+	MQTTPACKET_READ_COMPLETE
+};
+
+enum msgTypes
+{
+	CONNECT = 1, CONNACK, PUBLISH, PUBACK, PUBREC, PUBREL,
+	PUBCOMP, SUBSCRIBE, SUBACK, UNSUBSCRIBE, UNSUBACK,
+	PINGREQ, PINGRESP, DISCONNECT
+#if defined(MQTTV5)
+  , AUTH
+#endif
+};
+
+/**
+ * Bitfields for the MQTT header byte.
+ */
+typedef union
+{
+	unsigned char byte;	                /**< the whole byte */
+#if defined(REVERSED)
+	struct
+	{
+		unsigned int type : 4;			/**< message type nibble */
+		unsigned int dup : 1;				/**< DUP flag bit */
+		unsigned int qos : 2;				/**< QoS value, 0, 1 or 2 */
+		unsigned int retain : 1;		/**< retained flag bit */
+	} bits;
+#else
+	struct
+	{
+		unsigned int retain : 1;		/**< retained flag bit */
+		unsigned int qos : 2;				/**< QoS value, 0, 1 or 2 */
+		unsigned int dup : 1;				/**< DUP flag bit */
+		unsigned int type : 4;			/**< message type nibble */
+	} bits;
+#endif
+} MQTTHeader;
+
+typedef struct
+{
+	int32_t len;
+	char* data;
+} MQTTLenString;
+
+typedef struct
+{
+	char* cstring;
+	MQTTLenString lenstring;
+} MQTTString;
+
+#define MQTTString_initializer {NULL, {0, NULL}}
+
+int MQTTstrlen(MQTTString mqttstring);
+
+DLLExport int32_t MQTTSerialize_ack(unsigned char* buf, int32_t buflen, unsigned char type, unsigned char dup, unsigned short packetid);
+DLLExport int32_t MQTTDeserialize_ack(unsigned char* packettype, unsigned char* dup, unsigned short* packetid, unsigned char* buf, int32_t buflen);
+
+int32_t MQTTPacket_VBIlen(int32_t rem_len);
+int32_t MQTTPacket_len(int32_t rem_len);
+DLLExport int MQTTPacket_equals(MQTTString* a, char* b);
+
+DLLExport int32_t MQTTPacket_encode(unsigned char* buf, int32_t length);
+int32_t MQTTPacket_decode(int (*getcharfn)(unsigned char*, int), int32_t* value);
+int32_t MQTTPacket_decodeBuf(unsigned char* buf, int32_t* value);
+
+int readInt(unsigned char** pptr);
+char readChar(unsigned char** pptr);
+void writeChar(unsigned char** pptr, char c);
+void writeInt(unsigned char** pptr, int anInt);
+int readMQTTLenString(MQTTString* mqttstring, unsigned char** pptr, unsigned char* enddata);
+void writeCString(unsigned char** pptr, const char* string);
+void writeMQTTString(unsigned char** pptr, MQTTString mqttstring);
+
+DLLExport int MQTTPacket_read(unsigned char* buf, int32_t buflen, int (*getfn)(unsigned char*, int));
+
+typedef struct {
+	int (*getfn)(void *, unsigned char*, int); /* must return -1 for error, 0 for call again, or the number of bytes read */
+	void *sck;	/* pointer to whatever the system may use to identify the transport */
+	int multiplier;
+	int rem_len;
+	int32_t len;
+	char state;
+}MQTTTransport;
+
+int MQTTPacket_readnb(unsigned char* buf, int32_t buflen, MQTTTransport *trp);
+
+#ifdef __cplusplus /* If this is a C++ compiler, use C linkage */
+}
+#endif
+
+
+#endif /* MQTTPACKETCOMMON_H_ */
diff --git a/MQTTPacket/src/MQTTSerializePublish.c b/MQTTPacket/src/MQTTSerializePublish.c
index f0acb351..80f48e80 100644
--- a/MQTTPacket/src/MQTTSerializePublish.c
+++ b/MQTTPacket/src/MQTTSerializePublish.c
@@ -17,7 +17,7 @@
  *******************************************************************************/
 
 #if defined(MQTTV5)
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #else
 #include "MQTTPacket.h"
 #endif
diff --git a/MQTTPacket/src/MQTTSubscribeClient.c b/MQTTPacket/src/MQTTSubscribeClient.c
index a62360bc..371ce69a 100644
--- a/MQTTPacket/src/MQTTSubscribeClient.c
+++ b/MQTTPacket/src/MQTTSubscribeClient.c
@@ -16,7 +16,7 @@
  *******************************************************************************/
 
 #if defined(MQTTV5)
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #else
 #include "MQTTPacket.h"
 #endif
diff --git a/MQTTPacket/src/MQTTSubscribeServer.c b/MQTTPacket/src/MQTTSubscribeServer.c
index 23f8e1e4..789aa5aa 100644
--- a/MQTTPacket/src/MQTTSubscribeServer.c
+++ b/MQTTPacket/src/MQTTSubscribeServer.c
@@ -16,7 +16,7 @@
  *******************************************************************************/
 
 #if defined(MQTTV5)
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #else
 #include "MQTTPacket.h"
 #endif
diff --git a/MQTTPacket/src/MQTTUnsubscribeClient.c b/MQTTPacket/src/MQTTUnsubscribeClient.c
index 2def67fb..c3e4145f 100644
--- a/MQTTPacket/src/MQTTUnsubscribeClient.c
+++ b/MQTTPacket/src/MQTTUnsubscribeClient.c
@@ -16,7 +16,7 @@
  *******************************************************************************/
 
 #if defined(MQTTV5)
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #else
 #include "MQTTPacket.h"
 #endif
diff --git a/MQTTPacket/src/MQTTUnsubscribeServer.c b/MQTTPacket/src/MQTTUnsubscribeServer.c
index 529aae65..ec3c7364 100644
--- a/MQTTPacket/src/MQTTUnsubscribeServer.c
+++ b/MQTTPacket/src/MQTTUnsubscribeServer.c
@@ -16,7 +16,7 @@
  *******************************************************************************/
 
 #if defined(MQTTV5)
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #else
 #include "MQTTPacket.h"
 #endif
diff --git a/MQTTPacket/src/V5/MQTTV5Packet.h b/MQTTPacket/src/MQTTV5Packet.h
similarity index 82%
rename from MQTTPacket/src/V5/MQTTV5Packet.h
rename to MQTTPacket/src/MQTTV5Packet.h
index 14a96b6b..7fb5b504 100644
--- a/MQTTPacket/src/V5/MQTTV5Packet.h
+++ b/MQTTPacket/src/MQTTV5Packet.h
@@ -17,23 +17,21 @@
 #ifndef MQTTV5PACKET_H_
 #define MQTTV5PACKET_H_
 
-#include "MQTTPacket.h"
+#ifndef MQTTV5
+#define MQTTV5
+#endif
 
 #if defined(__cplusplus) /* If this is a C++ compiler, use C linkage */
 extern "C" {
 #endif
 
-#include "MQTTReasonCodes.h"
-
-#include "MQTTProperties.h"
-
-#include "MQTTV5Connect.h"
-
-#include "MQTTV5Publish.h"
-
-#include "MQTTV5Subscribe.h"
-
-#include "MQTTV5Unsubscribe.h"
+#include "MQTTPacketCommon.h"
+#include "V5/MQTTReasonCodes.h"
+#include "V5/MQTTProperties.h"
+#include "V5/MQTTV5Connect.h"
+#include "V5/MQTTV5Publish.h"
+#include "V5/MQTTV5Subscribe.h"
+#include "V5/MQTTV5Unsubscribe.h"
 
 void writeInt4(unsigned char** pptr, int anInt);
 int readInt4(unsigned char** pptr);
diff --git a/MQTTPacket/src/V3/MQTTConnect.h b/MQTTPacket/src/V3/MQTTConnect.h
new file mode 100644
index 00000000..cf84845c
--- /dev/null
+++ b/MQTTPacket/src/V3/MQTTConnect.h
@@ -0,0 +1,38 @@
+/*******************************************************************************
+ * Copyright (c) 2014, 2023 IBM Corp. and others
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ *
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *   http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * Contributors:
+ *    Ian Craggs - initial API and implementation and/or initial documentation
+ *    Ian Craggs - add connack return code definitions
+ *    Xiang Rong - 442039 Add makefile to Embedded C client
+ *    Ian Craggs - fix for issue #64, bit order in connack response
+ *******************************************************************************/
+
+#ifndef MQTTCONNECT_H_
+#define MQTTCONNECT_H_
+
+#include <stdint.h>
+#include "MQTTConnectCommon.h"
+
+#define MQTTPacket_connectData_initializer { {'M', 'Q', 'T', 'C'}, 4, {NULL, {0, NULL}}, 60, 1, 0, \
+		MQTTPacket_willOptions_initializer, {NULL, {0, NULL}}, {NULL, {0, NULL}} }
+
+DLLExport int MQTTSerialize_connect(unsigned char* buf, int32_t buflen, MQTTPacket_connectData* options);
+DLLExport int MQTTDeserialize_connect(MQTTPacket_connectData* data, unsigned char* buf, int32_t len);
+
+DLLExport int MQTTSerialize_connack(unsigned char* buf, int32_t buflen, unsigned char connack_rc, unsigned char sessionPresent);
+DLLExport int MQTTDeserialize_connack(unsigned char* sessionPresent, unsigned char* connack_rc, unsigned char* buf, int32_t buflen);
+
+DLLExport int MQTTSerialize_disconnect(unsigned char* buf, int32_t buflen);
+DLLExport int MQTTDeserialize_disconnect(unsigned char* buf, int32_t buflen);
+
+#endif /* MQTTCONNECT_H_ */
diff --git a/MQTTPacket/src/MQTTFormat.c b/MQTTPacket/src/V3/MQTTFormat.c
similarity index 98%
rename from MQTTPacket/src/MQTTFormat.c
rename to MQTTPacket/src/V3/MQTTFormat.c
index f4f2d779..ae07c8af 100644
--- a/MQTTPacket/src/MQTTFormat.c
+++ b/MQTTPacket/src/V3/MQTTFormat.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2014 IBM Corp.
+ * Copyright (c) 2014, 2023 IBM Corp.
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -33,7 +33,6 @@ const char* MQTTPacket_getName(unsigned short packetid)
 	return MQTTPacket_names[packetid];
 }
 
-
 int MQTTStringFormat_connect(char* strbuf, int strbuflen, MQTTPacket_connectData* data)
 {
 	int strindex = 0;
@@ -41,11 +40,7 @@ int MQTTStringFormat_connect(char* strbuf, int strbuflen, MQTTPacket_connectData
 	strindex = snprintf(strbuf, strbuflen,
 			"CONNECT MQTT version %d, client id %.*s, clean session %d, keep alive %d",
 			(int)data->MQTTVersion, (int) data->clientID.lenstring.len, data->clientID.lenstring.data,
-#if defined(MQTTV5)
-			(int)data->cleanstart, 
-#else
 			(int)data->cleansession, 
-#endif
 			data->keepAliveInterval);
 
 	if (data->willFlag)
@@ -63,14 +58,14 @@ int MQTTStringFormat_connect(char* strbuf, int strbuflen, MQTTPacket_connectData
 	return strindex;
 }
 
-
 int MQTTStringFormat_connack(char* strbuf, int strbuflen, unsigned char connack_rc, unsigned char sessionPresent)
 {
-	int strindex = snprintf(strbuf, strbuflen, "CONNACK session present %d, rc %d", sessionPresent, connack_rc);
+	int strindex = snprintf(strbuf, strbuflen, "CONNACK session present %d, rc %d", sessionPresent, 
+	connack_rc);
+
 	return strindex;
 }
 
-
 int MQTTStringFormat_publish(char* strbuf, int strbuflen, unsigned char dup, int qos, unsigned char retained,
 		unsigned short packetid, MQTTString topicName, unsigned char* payload, int payloadlen)
 {
@@ -91,7 +86,6 @@ int MQTTStringFormat_ack(char* strbuf, int strbuflen, unsigned char packettype,
 	return strindex;
 }
 
-
 int MQTTStringFormat_subscribe(char* strbuf, int strbuflen, unsigned char dup, unsigned short packetid, int count,
 		MQTTString topicFilters[], unsigned char requestedQoSs[])
 {
diff --git a/MQTTPacket/src/MQTTFormat.h b/MQTTPacket/src/V3/MQTTFormat.h
similarity index 100%
rename from MQTTPacket/src/MQTTFormat.h
rename to MQTTPacket/src/V3/MQTTFormat.h
diff --git a/MQTTPacket/src/MQTTPublish.h b/MQTTPacket/src/V3/MQTTPublish.h
similarity index 100%
rename from MQTTPacket/src/MQTTPublish.h
rename to MQTTPacket/src/V3/MQTTPublish.h
diff --git a/MQTTPacket/src/MQTTSubscribe.h b/MQTTPacket/src/V3/MQTTSubscribe.h
similarity index 97%
rename from MQTTPacket/src/MQTTSubscribe.h
rename to MQTTPacket/src/V3/MQTTSubscribe.h
index 18f53cf5..ae0e4a07 100644
--- a/MQTTPacket/src/MQTTSubscribe.h
+++ b/MQTTPacket/src/V3/MQTTSubscribe.h
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2014 IBM Corp.
+ * Copyright (c) 2014, 2023 IBM Corp.
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
diff --git a/MQTTPacket/src/MQTTUnsubscribe.h b/MQTTPacket/src/V3/MQTTUnsubscribe.h
similarity index 100%
rename from MQTTPacket/src/MQTTUnsubscribe.h
rename to MQTTPacket/src/V3/MQTTUnsubscribe.h
diff --git a/MQTTPacket/src/V5/MQTTProperties.h b/MQTTPacket/src/V5/MQTTProperties.h
index 39bf5061..6a1fd84d 100644
--- a/MQTTPacket/src/V5/MQTTProperties.h
+++ b/MQTTPacket/src/V5/MQTTProperties.h
@@ -14,6 +14,8 @@
  *    Ian Craggs - initial API and implementation and/or initial documentation
  *******************************************************************************/
 
+#ifndef MQTTPROPERTIES_H_
+#define MQTTPROPERTIES_H_
 
 enum MQTTPropertyNames {
   MQTTPROPERTY_CODE_PAYLOAD_FORMAT_INDICATOR = 1,
@@ -102,3 +104,5 @@ DLLExport int MQTTProperties_read(MQTTProperties* properties, unsigned char** pp
  * @return the `PropertyTypes` type of the property
  */
 DLLExport int MQTTProperty_getType(int identifier);
+
+#endif // MQTTPROPERTIES_H_
diff --git a/MQTTPacket/src/V5/MQTTReasonCodes.h b/MQTTPacket/src/V5/MQTTReasonCodes.h
index c303b6e7..9ded243c 100644
--- a/MQTTPacket/src/V5/MQTTReasonCodes.h
+++ b/MQTTPacket/src/V5/MQTTReasonCodes.h
@@ -13,6 +13,8 @@
  * Contributors:
  *    Ian Craggs - initial API and implementation and/or initial documentation
  *******************************************************************************/
+#ifndef MQTTREASONCODES_H_
+#define MQTTREASONCODES_H_
 
 /**
  * @brief MQTTv5 Reason Codes
@@ -65,3 +67,5 @@ enum MQTTReasonCodes {
   MQTTREASONCODE_SUBSCRIPTION_IDENTIFIERS_NOT_SUPPORTED = 161,
   MQTTREASONCODE_WILDCARD_SUBSCRIPTION_NOT_SUPPORTED = 162
 };
+
+#endif // MQTTREASONCODES_H_
diff --git a/MQTTPacket/src/V5/MQTTV5Connect.h b/MQTTPacket/src/V5/MQTTV5Connect.h
index bc6512e1..fdf5b01b 100644
--- a/MQTTPacket/src/V5/MQTTV5Connect.h
+++ b/MQTTPacket/src/V5/MQTTV5Connect.h
@@ -17,13 +17,13 @@
 #ifndef MQTT5CONNECT_H_
 #define MQTT5CONNECT_H_
 
-#include "MQTTConnect.h"
+#include "MQTTConnectCommon.h"
 
 DLLExport int32_t MQTTV5Serialize_connect(unsigned char* buf, int32_t buflen, MQTTPacket_connectData* options,
-  MQTTProperties* connectProperties, MQTTProperties* willProperties);
+  MQTTProperties* connectProperties);
 
-DLLExport int32_t MQTTV5Deserialize_connect(MQTTProperties* willProperties,
-  MQTTProperties* connectProperties, MQTTPacket_connectData* data, unsigned char* buf, int32_t len);
+DLLExport int32_t MQTTV5Deserialize_connect(MQTTProperties* connectProperties, MQTTPacket_connectData* data, 
+  unsigned char* buf, int32_t len);
 
 DLLExport int32_t MQTTV5Serialize_connack(unsigned char* buf, int32_t buflen, unsigned char connack_rc,
   unsigned char sessionPresent, MQTTProperties* connackProperties);
diff --git a/MQTTPacket/src/V5/MQTTV5Format.c b/MQTTPacket/src/V5/MQTTV5Format.c
new file mode 100644
index 00000000..447fe62f
--- /dev/null
+++ b/MQTTPacket/src/V5/MQTTV5Format.c
@@ -0,0 +1,272 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Microsoft Corporation. All rights reserved.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ *
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *   http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ *******************************************************************************/
+
+// TODO: Add MQTTv5 properties implementation (some of the code exists in v5log.h), application must provide memory.
+#include "StackTrace.h"
+#include "MQTTV5Packet.h"
+
+#include <string.h>
+
+// The index of each packet name as described by the MQTTv5.0 spec, section 2.1.2.
+// E.g. MQTTV5Packet_names[15] == "AUTH"
+const char* MQTTV5Packet_names[] =
+{
+	"RESERVED", "CONNECT", "CONNACK", "PUBLISH", "PUBACK", "PUBREC", "PUBREL",
+	"PUBCOMP", "SUBSCRIBE", "SUBACK", "UNSUBSCRIBE", "UNSUBACK",
+	"PINGREQ", "PINGRESP", "DISCONNECT", "AUTH"
+};
+
+
+const char* MQTTV5Packet_getName(unsigned short packetid)
+{
+	return MQTTV5Packet_names[packetid];
+}
+
+
+int MQTTV5StringFormat_connect(char* strbuf, int strbuflen, MQTTPacket_connectData* data)
+{
+	int strindex = 0;
+
+	strindex = snprintf(strbuf, strbuflen,
+			"CONNECT MQTT version %d, client id %.*s, clean start %d, keep alive %d",
+			(int)data->MQTTVersion, (int) data->clientID.lenstring.len, data->clientID.lenstring.data,
+			(int)data->cleanstart, data->keepAliveInterval);
+	if (data->willFlag)
+		strindex += snprintf(&strbuf[strindex], strbuflen - strindex,
+				", will QoS %d, will retain %d, will topic %.*s, will message %.*s",
+				data->will.qos, data->will.retained,
+				(int) data->will.topicName.lenstring.len, data->will.topicName.lenstring.data,
+				(int) data->will.message.lenstring.len, data->will.message.lenstring.data);
+	if (data->username.lenstring.data && data->username.lenstring.len > 0)
+		strindex += snprintf(&strbuf[strindex], strbuflen - strindex,
+				", user name %.*s", (int) data->username.lenstring.len, data->username.lenstring.data);
+	if (data->password.lenstring.data && data->password.lenstring.len > 0)
+		strindex += snprintf(&strbuf[strindex], strbuflen - strindex,
+				", password %.*s", (int) data->password.lenstring.len, data->password.lenstring.data);
+	return strindex;
+}
+
+
+int MQTTV5StringFormat_connack(char* strbuf, int strbuflen, enum MQTTReasonCodes reason_code, unsigned char sessionPresent)
+{
+	int strindex = snprintf(strbuf, strbuflen, "CONNACK session present %d, rc %d", sessionPresent, reason_code);
+	return strindex;
+}
+
+
+int MQTTV5StringFormat_publish(char* strbuf, int strbuflen, unsigned char dup, int qos, unsigned char retained,
+		unsigned short packetid, MQTTString topicName, unsigned char* payload, int payloadlen)
+{
+	int strindex = snprintf(strbuf, strbuflen,
+				"PUBLISH dup %d, QoS %d, retained %d, packet id %d, topic %.*s, payload length %d, payload %.*s",
+				dup, qos, retained, packetid,
+				(topicName.lenstring.len < 20) ? (int) topicName.lenstring.len : 20, topicName.lenstring.data,
+				(int) payloadlen, (payloadlen < 20) ? (int) payloadlen : 20, payload);
+	return strindex;
+}
+
+
+int MQTTV5StringFormat_ack(char* strbuf, int strbuflen, unsigned char packettype, unsigned char dup, unsigned char reason, unsigned short packetid)
+{
+	int strindex = snprintf(strbuf, strbuflen, "%s, packet id %d reason %d", MQTTV5Packet_names[packettype], packetid, reason);
+	if (dup)
+		strindex += snprintf(strbuf + strindex, strbuflen - strindex, ", dup %d", dup);
+	return strindex;
+}
+
+
+int MQTTV5StringFormat_subscribe(char* strbuf, int strbuflen, unsigned char dup, unsigned short packetid, int count,
+		MQTTString topicFilters[], unsigned char requestedQoSs[])
+{
+	return snprintf(strbuf, strbuflen,
+		"SUBSCRIBE dup %d, packet id %d count %d topic %.*s qos %d",
+		dup, packetid, count,
+		(int) topicFilters[0].lenstring.len, topicFilters[0].lenstring.data,
+		requestedQoSs[0]);
+}
+
+
+int MQTTV5StringFormat_suback(char* strbuf, int strbuflen, unsigned short packetid, int count, unsigned char* grantedQoSs)
+{
+	return snprintf(strbuf, strbuflen,
+		"SUBACK packet id %d count %d granted qos %d", packetid, count, grantedQoSs[0]);
+}
+
+
+int MQTTV5StringFormat_unsubscribe(char* strbuf, int strbuflen, unsigned char dup, unsigned short packetid,
+		int count, MQTTString topicFilters[])
+{
+	return snprintf(strbuf, strbuflen,
+					"UNSUBSCRIBE dup %d, packet id %d count %d topic %.*s",
+					dup, packetid, count,
+					(int) topicFilters[0].lenstring.len, topicFilters[0].lenstring.data);
+}
+
+
+#if defined(MQTT_CLIENT)
+char* MQTTV5Format_toClientString(char* strbuf, int strbuflen, unsigned char* buf, int32_t buflen)
+{
+	int index = 0;
+	int rem_length = 0;
+	MQTTHeader header = {0};
+	int strindex = 0;
+
+	header.byte = buf[index++];
+	index += MQTTPacket_decodeBuf(&buf[index], &rem_length);
+
+	switch (header.bits.type)
+	{
+
+	case CONNACK:
+	{
+		unsigned char sessionPresent, connack_rc;
+#if defined(MQTT5)
+
+#else
+		if (MQTTV5Deserialize_connack(NULL, &sessionPresent, &connack_rc, buf, buflen) == 1)
+			strindex = MQTTV5StringFormat_connack(strbuf, strbuflen, connack_rc, sessionPresent);
+#endif
+	}
+	break;
+	case PUBLISH:
+	{
+		unsigned char dup, retained, *payload, qos;
+		unsigned short packetid;
+		int32_t payloadlen;
+		MQTTString topicName = MQTTString_initializer;
+		if (MQTTV5Deserialize_publish(&dup, &qos, &retained, &packetid, &topicName,
+				NULL, &payload, &payloadlen, buf, buflen) == 1)
+			strindex = MQTTV5StringFormat_publish(strbuf, strbuflen, dup, qos, retained, packetid,
+					topicName, payload, payloadlen);
+	}
+	break;
+	case PUBACK:
+	case PUBREC:
+	case PUBREL:
+	case PUBCOMP:
+	{
+		unsigned char packettype, dup, reason;
+		unsigned short packetid;
+		if (MQTTV5Deserialize_ack(&packettype, &dup, &packetid, &reason, NULL, buf, buflen) == 1)
+			strindex = MQTTV5StringFormat_ack(strbuf, strbuflen, packettype, dup, reason, packetid);
+	}
+	break;
+	case SUBACK:
+	{
+		unsigned short packetid;
+		int maxcount = 1, count = 0;
+		unsigned char grantedQoSs[1];
+		unsigned char reasonCodes[1];
+		if (MQTTV5Deserialize_suback(&packetid, NULL, maxcount, &count, reasonCodes, buf, buflen) == 1)
+			strindex = MQTTV5StringFormat_suback(strbuf, strbuflen, packetid, count, grantedQoSs);
+	}
+	break;
+	case UNSUBACK:
+	{
+		unsigned short packetid;
+		int maxcount = 1, count = 0;
+		unsigned char reasonCodes[1];
+
+		if (MQTTV5Deserialize_unsuback(&packetid, NULL, maxcount, &count, reasonCodes, buf, buflen) == 1)
+			strindex = MQTTV5StringFormat_ack(strbuf, strbuflen, UNSUBACK, 0, reasonCodes[0], packetid);
+	}
+	break;
+	case PINGREQ:
+	case PINGRESP:
+	case DISCONNECT:
+		strindex = snprintf(strbuf, strbuflen, "%s", MQTTV5Packet_names[header.bits.type]);
+		break;
+	}
+	return strbuf;
+}
+#endif
+
+#if defined(MQTT_SERVER)
+char* MQTTV5Format_toServerString(char* strbuf, int strbuflen, unsigned char* buf, int32_t buflen)
+{
+	int index = 0;
+	int rem_length = 0;
+	MQTTHeader header = {0};
+	int strindex = 0;
+
+	header.byte = buf[index++];
+	index += MQTTPacket_decodeBuf(&buf[index], &rem_length);
+
+	switch (header.bits.type)
+	{
+	case CONNECT:
+	{
+		MQTTPacket_connectData data;
+		int rc;
+		if ((rc = MQTTV5Deserialize_connect(NULL, &data, buf, buflen)) == 1)
+			strindex = MQTTV5StringFormat_connect(strbuf, strbuflen, &data);
+	}
+	break;
+	case PUBLISH:
+	{
+		unsigned char dup, retained, *payload, qos;
+		unsigned short packetid;
+		int32_t payloadlen;
+		MQTTString topicName = MQTTString_initializer;
+		if (MQTTV5Deserialize_publish(&dup, &qos, &retained, &packetid, &topicName, NULL,
+				&payload, &payloadlen, buf, buflen) == 1)
+			strindex = MQTTV5StringFormat_publish(strbuf, strbuflen, dup, qos, retained, packetid,
+					topicName, payload, payloadlen);
+	}
+	break;
+	case PUBACK:
+	case PUBREC:
+	case PUBREL:
+	case PUBCOMP:
+	{
+		unsigned char packettype, dup, reason;
+		unsigned short packetid;
+		if (MQTTV5Deserialize_ack(&packettype, &dup, &packetid, &reason, NULL, buf, buflen) == 1)
+			strindex = MQTTV5StringFormat_ack(strbuf, strbuflen, packettype, dup, reason, packetid);
+	}
+	break;
+	case SUBSCRIBE:
+	{
+		unsigned char dup;
+		unsigned short packetid;
+		int maxcount = 1, count = 0;
+		MQTTString topicFilters[1];
+		unsigned char requestedQoSs[1];
+		MQTTSubscribe_options sub_options[1];
+
+		if (MQTTV5Deserialize_subscribe(&dup, &packetid, NULL, maxcount, &count,
+				topicFilters, requestedQoSs, sub_options, buf, buflen) == 1)
+			strindex = MQTTV5StringFormat_subscribe(strbuf, strbuflen, dup, packetid, count, topicFilters, requestedQoSs);;
+	}
+	break;
+	case UNSUBSCRIBE:
+	{
+		unsigned char dup;
+		unsigned short packetid;
+		int maxcount = 1, count = 0;
+		MQTTString topicFilters[1];
+		if (MQTTV5Deserialize_unsubscribe(&dup, &packetid, NULL, maxcount, &count, topicFilters, buf, buflen) == 1)
+			strindex =  MQTTV5StringFormat_unsubscribe(strbuf, strbuflen, dup, packetid, count, topicFilters);
+	}
+	break;
+	case PINGREQ:
+	case PINGRESP:
+	case DISCONNECT:
+		strindex = snprintf(strbuf, strbuflen, "%s", MQTTV5Packet_names[header.bits.type]);
+		break;
+	}
+	strbuf[strbuflen] = '\0';
+	return strbuf;
+}
+#endif
diff --git a/MQTTPacket/src/V5/MQTTV5Format.h b/MQTTPacket/src/V5/MQTTV5Format.h
new file mode 100644
index 00000000..51797730
--- /dev/null
+++ b/MQTTPacket/src/V5/MQTTV5Format.h
@@ -0,0 +1,35 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Microsoft Corporation. All rights reserved.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ *
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *   http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ *******************************************************************************/
+
+#if !defined(MQTTV5FORMAT_H)
+#define MQTTV5FORMAT_H
+
+#include "StackTrace.h"
+#include "MQTTV5Packet.h"
+
+const char* MQTTV5Packet_getName(unsigned short packetid);
+int MQTTV5StringFormat_connect(char* strbuf, int strbuflen, MQTTPacket_connectData* data);
+int MQTTV5StringFormat_connack(char* strbuf, int strbuflen, unsigned char connack_rc, unsigned char sessionPresent);
+int MQTTV5StringFormat_publish(char* strbuf, int strbuflen, unsigned char dup, int qos, unsigned char retained,
+		unsigned short packetid, MQTTString topicName, unsigned char* payload, int payloadlen);
+int MQTTV5StringFormat_ack(char* strbuf, int strbuflen, unsigned char packettype, unsigned char dup, unsigned short packetid);
+int MQTTV5StringFormat_subscribe(char* strbuf, int strbuflen, unsigned char dup, unsigned short packetid, int count,
+		MQTTString topicFilters[], unsigned char requestedQoSs[]);
+int MQTTV5StringFormat_suback(char* strbuf, int strbuflen, unsigned short packetid, int count, unsigned char* grantedQoSs);
+int MQTTV5StringFormat_unsubscribe(char* strbuf, int strbuflen, unsigned char dup, unsigned short packetid,
+		int count, MQTTString topicFilters[]);
+char* MQTTV5Format_toClientString(char* strbuf, int strbuflen, unsigned char* buf, int32_t buflen);
+char* MQTTV5Format_toServerString(char* strbuf, int strbuflen, unsigned char* buf, int32_t buflen);
+
+#endif
diff --git a/MQTTPacket/src/V5/MQTTV5Publish.h b/MQTTPacket/src/V5/MQTTV5Publish.h
index 91a6c02a..84d1c697 100644
--- a/MQTTPacket/src/V5/MQTTV5Publish.h
+++ b/MQTTPacket/src/V5/MQTTV5Publish.h
@@ -24,8 +24,6 @@
   #define DLLExport
 #endif
 
-#include "MQTTPublish.h"
-
 DLLExport int32_t MQTTV5Serialize_publish(unsigned char* buf, int32_t buflen, unsigned char dup, unsigned char qos, unsigned char retained,
   unsigned short packetid, MQTTString topicName, MQTTProperties* props, unsigned char* payload, int32_t payloadlen);
 
diff --git a/MQTTPacket/test/CMakeLists.txt b/MQTTPacket/test/CMakeLists.txt
index 6e51141b..a18ecc7c 100644
--- a/MQTTPacket/test/CMakeLists.txt
+++ b/MQTTPacket/test/CMakeLists.txt
@@ -12,6 +12,7 @@ ELSE ()
   SET(CERTDIR $ENV{TRAVIS_BUILD_DIR}/test/ssl)
 ENDIF ()
 
+# transport.h/c are reused from ../samples:
 include_directories(../src ../src/V5 ../samples)
 
 ADD_EXECUTABLE(
@@ -38,30 +39,6 @@ SET_TESTS_PROPERTIES(
 	PROPERTIES TIMEOUT 540
 )
 
-ADD_EXECUTABLE(
-	test15
-	test1.c
-)
-
-# Disabling deprecation warnings:
-#  warning: ‘ftime’ is deprecated [-Wdeprecated-declarations]
-target_compile_options(test15 PRIVATE -Wno-deprecated-declarations)
-
-TARGET_LINK_LIBRARIES(
-	test15
-	paho-embed-mqtt5c
-)
-
-ADD_TEST(
-	NAME test15
-	COMMAND "test15" "--connection" ${MQTT_TEST_BROKER}
-)
-
-SET_TESTS_PROPERTIES(
-	test15
-	PROPERTIES TIMEOUT 540
-)
-
 ADD_EXECUTABLE(
 	test2
 	test2.c
@@ -90,6 +67,7 @@ SET_TESTS_PROPERTIES(
 ADD_EXECUTABLE(
 	test3
 	test3.c
+	../samples/transport.c
 )
 
 # Disabling deprecation warnings:
diff --git a/MQTTPacket/test/test1.c b/MQTTPacket/test/test1.c
index a04c4a55..73e404ad 100644
--- a/MQTTPacket/test/test1.c
+++ b/MQTTPacket/test/test1.c
@@ -273,9 +273,6 @@ int checkConnectPackets(MQTTPacket_connectData* before, MQTTPacket_connectData*
 	assert("struct_ids should be the same",
 			memcmp(before->struct_id, after->struct_id, 4) == 0, "struct_ids were different %.4s\n", after->struct_id);
 
-	assert("struct_versions should be the same",
-			before->struct_version == after->struct_version, "struct_versions were different\n", rc);
-
 	assert("MQTT versions should be the same",
 			before->MQTTVersion == after->MQTTVersion, "MQTT versions were different\n", rc);
 
@@ -296,9 +293,6 @@ int checkConnectPackets(MQTTPacket_connectData* before, MQTTPacket_connectData*
 		assert("will struct_ids should be the same",
 				memcmp(before->will.struct_id, after->will.struct_id, 4) == 0, "will struct_ids were different %.4s\n", after->struct_id);
 
-		assert("will struct_versions should be the same",
-				before->will.struct_version == after->will.struct_version, "will struct_versions were different\n", rc);
-
 		assert("topic names should be the same",
 				checkMQTTStrings(before->will.topicName, after->will.topicName), "topic names were different\n", rc);
 
diff --git a/MQTTPacket/test/test2.c b/MQTTPacket/test/test2.c
index 1c890ac3..b051b8db 100644
--- a/MQTTPacket/test/test2.c
+++ b/MQTTPacket/test/test2.c
@@ -18,7 +18,7 @@
   Tests for MQTTV5 serialization and deserialization
 ***/
 
-#include "V5/MQTTV5Packet.h"
+#include "MQTTV5Packet.h"
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -276,9 +276,6 @@ int checkConnectPackets(MQTTPacket_connectData* before, MQTTPacket_connectData*
 	assert("struct_ids should be the same",
 			memcmp(before->struct_id, after->struct_id, 4) == 0, "struct_ids were different %.4s\n", after->struct_id);
 
-	assert("struct_versions should be the same",
-			before->struct_version == after->struct_version, "struct_versions were different\n", rc);
-
 	assert("MQTT versions should be the same",
 			before->MQTTVersion == after->MQTTVersion, "MQTT versions were different\n", rc);
 
@@ -288,8 +285,8 @@ int checkConnectPackets(MQTTPacket_connectData* before, MQTTPacket_connectData*
 	assert("keepAliveIntervals should be the same",
 			before->keepAliveInterval == after->keepAliveInterval, "keepAliveIntervals were different %d\n", after->keepAliveInterval);
 
-	assert("cleansessions should be the same",
-			before->cleansession == after->cleansession, "cleansessions were different\n", rc);
+	assert("cleanstarts should be the same",
+			before->cleanstart == after->cleanstart, "cleanstarts were different\n", rc);
 
 	assert("willFlags should be the same",
 				before->willFlag == after->willFlag, "willFlags were different\n", rc);
@@ -299,9 +296,6 @@ int checkConnectPackets(MQTTPacket_connectData* before, MQTTPacket_connectData*
 		assert("will struct_ids should be the same",
 				memcmp(before->will.struct_id, after->will.struct_id, 4) == 0, "will struct_ids were different %.4s\n", after->struct_id);
 
-		assert("will struct_versions should be the same",
-				before->will.struct_version == after->will.struct_version, "will struct_versions were different\n", rc);
-
 		assert("topic names should be the same",
 				checkMQTTStrings(before->will.topicName, after->will.topicName), "topic names were different\n", rc);
 
@@ -391,7 +385,7 @@ int test1(struct Options options)
 	data.clientID.cstring = "my clientid";
 
 	data.keepAliveInterval = 20;
-	data.cleansession = 1;
+	data.cleanstart = 1;
 	data.username.cstring = "testuser";
 	data.password.cstring = "testpassword";
 
@@ -400,11 +394,13 @@ int test1(struct Options options)
 	data.will.qos = 1;
 	data.will.retained = 0;
 	data.will.topicName.cstring = "will topic";
+	data.will.properties = &willProperties;
 
-	rc = MQTTV5Serialize_connect(buf, buflen, &data, &connectProperties, &willProperties);
+	rc = MQTTV5Serialize_connect(buf, buflen, &data, &connectProperties);
 	assert("good rc from serialize connect", rc > 0, "rc was %d\n", rc);
 
-	rc = MQTTV5Deserialize_connect(&outWillProperties, &outConnectProperties, &data_after, buf, buflen);
+	data_after.will.properties = &outWillProperties;
+	rc = MQTTV5Deserialize_connect(&outConnectProperties, &data_after, buf, buflen);
 	assert("good rc from deserialize connect", rc == 1, "rc was %d\n", rc);
 
 	/* data after should be the same as data before */
diff --git a/MQTTPacket/test/test3.c b/MQTTPacket/test/test3.c
index ba7577e6..b921c3a0 100644
--- a/MQTTPacket/test/test3.c
+++ b/MQTTPacket/test/test3.c
@@ -266,7 +266,7 @@ int test1(struct Options options)
 
 	data.clientID.cstring = "mqtt5_test3_test1";
 	data.keepAliveInterval = 20;
-	data.cleansession = 1;
+	data.cleanstart = 1;
 	data.username.cstring = "testuser";
 	data.password.cstring = "testpassword";
 	data.MQTTVersion = 5;
@@ -287,7 +287,7 @@ int test1(struct Options options)
 	rc = MQTTProperties_add(&properties, &one);
 	assert("add properties rc should be 0",  rc == 0, "rc was different %d\n", rc);
 
-	len = MQTTV5Serialize_connect((unsigned char *)buf, buflen, &data, &properties, NULL);
+	len = MQTTV5Serialize_connect((unsigned char *)buf, buflen, &data, &properties);
 	rc = transport_sendPacketBuffer(mysock, buf, len);
 	assert("rc and len should be the same",  rc == len, "rc was different %d\n", rc);