diff --git a/src/core/operations/MQTTPublish.mjs b/src/core/operations/MQTTPublish.mjs
index af2de3bf..bf9751ee 100644
--- a/src/core/operations/MQTTPublish.mjs
+++ b/src/core/operations/MQTTPublish.mjs
@@ -1,6 +1,6 @@
 /**
  * @author Configured Things Ltd. [getconfigured@configuredthings.com]
- * @copyright Crown Copyright 2024
+ * @copyright Crown Copyright 2025
  * @license Apache-2.0
  */
 
@@ -24,8 +24,8 @@ class MQTTPublish extends Operation {
         this.module = "MQTT";
         this.description = "Publishes a message to an MQTT broker";
         this.infoURL = "https://en.wikipedia.org/wiki/MQTT";
-        this.inputType = "String";
-        this.outputType = "String";
+        this.inputType = "ArrayBuffer";
+        this.outputType = "ArrayBuffer";
         this.args = [
             {
                 name: "MQTT broker URL",
@@ -41,19 +41,19 @@ class MQTTPublish extends Operation {
     }
 
     /**
-     * @param {String} input
+     * @param {ArrayBuffer} input
      * @param {Object[]} args
-     * @returns {String}
+     * @returns {ArrayBuffer}
      */
     run(input, args) {
         const [broker, topic] = args;
-        const mqttUrlRegex = /^(ws|mqtt)s?:\/\/(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]{0,61}[a-zA-Z0-9])(\.([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]{0,61}[a-zA-Z0-9]))*|([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])(\.([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])){3}|(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])))(:([1-9][0-9]{0,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]))?$/;
+        const mqttUrlRegex = /^(ws|mqtt)s?:\/\/(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]{0,61}[a-zA-Z0-9])(\.([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]{0,61}[a-zA-Z0-9]))*|([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])(\.([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])){3}|(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])))(:([1-9][0-9]{0,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5]))?/;
         const mqttTopicRegex = /^[\u0000-\uFFFF]+(\/[\u0000-\uFFFF]+)+$/;
         if (mqttUrlRegex.test(broker)) {
             if (mqttTopicRegex.test(broker)) {
                 const client = mqtt.connect(broker);
                 client.on("connect", () => {
-                    client.publish(topic, input);
+                    client.publish(topic, Buffer.from(input));
                     client.end();
                 });
             } else throw new OperationError(`Invalid MQTT topic name - ${topic}`);