diff --git a/src/Clients.h b/src/Clients.h
index 67489582..577551ee 100644
--- a/src/Clients.h
+++ b/src/Clients.h
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2023 IBM Corp. and Ian Craggs
+ * Copyright (c) 2009, 2024 IBM Corp. and Ian Craggs
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
@@ -114,8 +114,9 @@ typedef struct
 
 /**
  * Data related to one client
+ * The entire structure is initialized to 0 on creation, so all fields default to 0.
  */
-typedef struct
+typedef struct Clients
 {
 	char* clientID;					      /**< the string id of the client */
 	const char* username;					/**< MQTT v3.1 user name */
@@ -132,6 +133,7 @@ typedef struct
 	networkHandles net;             /**< network info for this client */
 	int msgID;                      /**< the MQTT message id */
 	int keepAliveInterval;          /**< the MQTT keep alive interval */
+	int savedKeepAliveInterval;     /**< saved keep alive interval, in case reset by server keep alive */
 	int retryInterval;              /**< the MQTT retry interval for QoS > 0 */
 	int maxInflightMessages;        /**< the max number of inflight outbound messages we allow */
 	willMessages* will;             /**< the MQTT will message, if any */
diff --git a/src/MQTTAsync.c b/src/MQTTAsync.c
index c6a11f6d..8ab3d5fc 100644
--- a/src/MQTTAsync.c
+++ b/src/MQTTAsync.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2023 IBM Corp., Ian Craggs and others
+ * Copyright (c) 2009, 2024 IBM Corp., Ian Craggs and others
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
@@ -668,7 +668,7 @@ int MQTTAsync_connect(MQTTAsync handle, const MQTTAsync_connectOptions* options)
 	if (locked)
 		MQTTAsync_unlock_mutex(mqttasync_mutex);
 
-	m->c->keepAliveInterval = options->keepAliveInterval;
+	m->c->keepAliveInterval = m->c->savedKeepAliveInterval = options->keepAliveInterval;
 	setRetryLoopInterval(options->keepAliveInterval);
 	m->c->cleansession = options->cleansession;
 	m->c->maxInflightMessages = options->maxInflight;
diff --git a/src/MQTTAsyncUtils.c b/src/MQTTAsyncUtils.c
index 29117fcc..6605014d 100644
--- a/src/MQTTAsyncUtils.c
+++ b/src/MQTTAsyncUtils.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2023 IBM Corp., Ian Craggs and others
+ * Copyright (c) 2009, 2024 IBM Corp., Ian Craggs and others
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
@@ -1998,6 +1998,26 @@ static int MQTTAsync_completeConnection(MQTTAsyncs* m, Connack* connack)
 				if (m->c->connected != 1)
 					rc = MQTTASYNC_DISCONNECTED;
 			}
+			if (m->c->MQTTVersion == MQTTVERSION_5)
+			{
+				if (MQTTProperties_hasProperty(&connack->properties, MQTTPROPERTY_CODE_SERVER_KEEP_ALIVE))
+				{
+					/* update the keep alive from the server keep alive */
+					int server_keep_alive = MQTTProperties_getNumericValue(&connack->properties, MQTTPROPERTY_CODE_SERVER_KEEP_ALIVE);
+					if (server_keep_alive != -999999)
+					{
+						Log(LOG_PROTOCOL, -1, "Setting keep alive interval to server keep alive %d", server_keep_alive);
+						m->c->keepAliveInterval = server_keep_alive;
+					}
+				}
+				else if (m->c->keepAliveInterval != m->c->savedKeepAliveInterval)
+				{
+					/* if the keep alive has been previously updated with a server keep alive, but there is no server keep alive
+					on this connect, reset it to the value requested in the original connect API */
+					Log(LOG_PROTOCOL, -1, "Resetting keep alive interval to %d", m->c->savedKeepAliveInterval);
+					m->c->keepAliveInterval = m->c->savedKeepAliveInterval;
+				}
+			}
 		}
 		m->pack = NULL;
 #if !defined(_WIN32) && !defined(_WIN64)
diff --git a/src/MQTTClient.c b/src/MQTTClient.c
index b6a7714b..b80b0c08 100644
--- a/src/MQTTClient.c
+++ b/src/MQTTClient.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2023 IBM Corp., Ian Craggs and others
+ * Copyright (c) 2009, 2024 IBM Corp., Ian Craggs and others
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
@@ -1428,7 +1428,7 @@ static MQTTResponse MQTTClient_connectURIVersion(MQTTClient handle, MQTTClient_c
 				m->c->connected = 1;
 				m->c->good = 1;
 				m->c->connect_state = NOT_IN_PROGRESS;
-				if (MQTTVersion == 4)
+				if (MQTTVersion >= MQTTVERSION_3_1_1)
 					sessionPresent = connack->flags.bits.sessionPresent;
 				if (m->c->cleansession || m->c->cleanstart)
 					rc = MQTTClient_cleanSession(m->c);
@@ -1454,6 +1454,24 @@ static MQTTResponse MQTTClient_connectURIVersion(MQTTClient handle, MQTTClient_c
 						goto exit;
 					}
 					*resp.properties = MQTTProperties_copy(&connack->properties);
+
+					if (MQTTProperties_hasProperty(&connack->properties, MQTTPROPERTY_CODE_SERVER_KEEP_ALIVE))
+					{
+						/* update the keep alive from the server keep alive */
+						int server_keep_alive = MQTTProperties_getNumericValue(&connack->properties, MQTTPROPERTY_CODE_SERVER_KEEP_ALIVE);
+						if (server_keep_alive != -999999)
+						{
+							Log(LOG_PROTOCOL, -1, "Setting keep alive interval to server keep alive %d", server_keep_alive);
+							m->c->keepAliveInterval = server_keep_alive;
+						}
+					}
+					else if (m->c->keepAliveInterval != m->c->savedKeepAliveInterval)
+					{
+						/* if the keep alive has been previously updated with a server keep alive, but there is no server keep alive
+						on this connect, reset it to the value requested in the original connect API */
+						Log(LOG_PROTOCOL, -1, "Resetting keep alive interval to %d", m->c->savedKeepAliveInterval);
+						m->c->keepAliveInterval = m->c->savedKeepAliveInterval;
+					}
 				}
 			}
 			MQTTPacket_freeConnack(connack);
@@ -1507,7 +1525,7 @@ static MQTTResponse MQTTClient_connectURI(MQTTClient handle, MQTTClient_connectO
 	start = MQTTTime_start_clock();
 
 	m->currentServerURI = serverURI;
-	m->c->keepAliveInterval = options->keepAliveInterval;
+	m->c->keepAliveInterval = m->c->savedKeepAliveInterval = options->keepAliveInterval;
 	m->c->retryInterval = options->retryInterval;
 	setRetryLoopInterval(options->keepAliveInterval);
 	m->c->MQTTVersion = options->MQTTVersion;