diff --git a/src/config/settings.h b/src/config/settings.h
index 25891813..d262ea33 100644
--- a/src/config/settings.h
+++ b/src/config/settings.h
@@ -123,6 +123,7 @@ typedef struct {
 typedef struct {
     char broker[MQTT_ADDR_LEN];
     uint16_t port;
+    char clientId[MQTT_CLIENTID_LEN];
     char user[MQTT_USER_LEN];
     char pwd[MQTT_PWD_LEN];
     char topic[MQTT_TOPIC_LEN];
diff --git a/src/defines.h b/src/defines.h
index d060515b..c97d069d 100644
--- a/src/defines.h
+++ b/src/defines.h
@@ -85,6 +85,7 @@ enum {MQTT_STATUS_OFFLINE = 0, MQTT_STATUS_PARTIAL, MQTT_STATUS_ONLINE};
 #define NTP_ADDR_LEN            32 // DNS Name
 
 #define MQTT_ADDR_LEN           64 // DNS Name
+#define MQTT_CLIENTID_LEN       65
 #define MQTT_USER_LEN           65 // there is another byte necessary for \0
 #define MQTT_PWD_LEN            65
 #define MQTT_TOPIC_LEN          65
diff --git a/src/publisher/pubMqtt.h b/src/publisher/pubMqtt.h
index 0e160f73..65dfef28 100644
--- a/src/publisher/pubMqtt.h
+++ b/src/publisher/pubMqtt.h
@@ -76,17 +76,23 @@ class PubMqtt {
 
             if((strlen(mCfgMqtt->user) > 0) && (strlen(mCfgMqtt->pwd) > 0))
                 mClient.setCredentials(mCfgMqtt->user, mCfgMqtt->pwd);
-            snprintf(mClientId, 24, "%s-", mDevName);
-            uint8_t pos = strlen(mClientId);
-            mClientId[pos++] = WiFi.macAddress().substring( 9, 10).c_str()[0];
-            mClientId[pos++] = WiFi.macAddress().substring(10, 11).c_str()[0];
-            mClientId[pos++] = WiFi.macAddress().substring(12, 13).c_str()[0];
-            mClientId[pos++] = WiFi.macAddress().substring(13, 14).c_str()[0];
-            mClientId[pos++] = WiFi.macAddress().substring(15, 16).c_str()[0];
-            mClientId[pos++] = WiFi.macAddress().substring(16, 17).c_str()[0];
-            mClientId[pos++] = '\0';
-
-            mClient.setClientId(mClientId);
+            if(strlen(mCfgMqtt->clientId) > 0)
+            {
+                snprintf(mClientId, 24, "%s-", mCfgMqtt->clientId);
+                mClient.setClientId(mCfgMqtt->clientId);
+            }else{
+                snprintf(mClientId, 24, "%s-", mDevName);
+                uint8_t pos = strlen(mClientId);
+                mClientId[pos++] = WiFi.macAddress().substring( 9, 10).c_str()[0];
+                mClientId[pos++] = WiFi.macAddress().substring(10, 11).c_str()[0];
+                mClientId[pos++] = WiFi.macAddress().substring(12, 13).c_str()[0];
+                mClientId[pos++] = WiFi.macAddress().substring(13, 14).c_str()[0];
+                mClientId[pos++] = WiFi.macAddress().substring(15, 16).c_str()[0];
+                mClientId[pos++] = WiFi.macAddress().substring(16, 17).c_str()[0];
+                mClientId[pos++] = '\0';
+
+                mClient.setClientId(mClientId);
+            }
             mClient.setServer(mCfgMqtt->broker, mCfgMqtt->port);
             mClient.setWill(mLwtTopic, QOS_0, true, mqttStr[MQTT_STR_LWT_NOT_CONN]);
             mClient.onConnect(std::bind(&PubMqtt::onConnect, this, std::placeholders::_1));
diff --git a/src/web/RestApi.h b/src/web/RestApi.h
index fba6486e..74d9934b 100644
--- a/src/web/RestApi.h
+++ b/src/web/RestApi.h
@@ -385,6 +385,7 @@ class RestApi {
 
         void getMqtt(JsonObject obj) {
             obj[F("broker")]     = String(mConfig->mqtt.broker);
+            obj[F("clientId")]   = String(mConfig->mqtt.clientId);
             obj[F("port")]       = String(mConfig->mqtt.port);
             obj[F("user")]       = String(mConfig->mqtt.user);
             obj[F("pwd")]        = (strlen(mConfig->mqtt.pwd) > 0) ? F("{PWD}") : String("");
diff --git a/src/web/html/setup.html b/src/web/html/setup.html
index 52c4634d..c2bc863d 100644
--- a/src/web/html/setup.html
+++ b/src/web/html/setup.html
@@ -249,6 +249,10 @@
                             <div class="col-12 col-sm-3 my-2">Port</div>
                             <div class="col-12 col-sm-9"><input type="number" name="mqttPort"/></div>
                         </div>
+                        <div class="row mb-3">
+                            <div class="col-12 col-sm-3 my-2">Client Id (optional)</div>
+                            <div class="col-12 col-sm-9"><input type="text" name="clientId"/></div>
+                        </div>
                         <div class="row mb-3">
                             <div class="col-12 col-sm-3 my-2">Username (optional)</div>
                             <div class="col-12 col-sm-9"><input type="text" name="mqttUser"/></div>
@@ -696,7 +700,7 @@
             }
 
             function parseMqtt(obj) {
-                for(var i of [["Addr", "broker"], ["Port", "port"], ["User", "user"], ["Pwd", "pwd"], ["Topic", "topic"], ["Interval", "interval"]])
+                for(var i of [["Addr", "broker"], ["Port", "port"], ["ClientId", "clientId"], ["User", "user"], ["Pwd", "pwd"], ["Topic", "topic"], ["Interval", "interval"]])
                     document.getElementsByName("mqtt"+i[0])[0].value = obj[i[1]];
             }
 
diff --git a/src/web/web.h b/src/web/web.h
index a289f230..7ff90324 100644
--- a/src/web/web.h
+++ b/src/web/web.h
@@ -582,6 +582,7 @@ class Web {
                 addr.toCharArray(mConfig->mqtt.broker, MQTT_ADDR_LEN);
             } else
                 mConfig->mqtt.broker[0] = '\0';
+            request->arg("mqttClientId").toCharArray(mConfig->mqtt.clientId, MQTT_CLIENTID_LEN);
             request->arg("mqttUser").toCharArray(mConfig->mqtt.user, MQTT_USER_LEN);
             if (request->arg("mqttPwd") != "{PWD}")
                 request->arg("mqttPwd").toCharArray(mConfig->mqtt.pwd, MQTT_PWD_LEN);