diff --git a/lib/utils.js b/lib/utils.js
index ea7c8dbf..84f9f5cb 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -3,12 +3,15 @@
 const { Transform, Writable } = require('stream')
 
 function validateTopic (topic, message) {
+
+  if (!topic || topic.length === 0) { // [MQTT-3.8.3-3]
+    return new Error('impossible to ' + message + ' to an empty topic')
+  }
+
   const end = topic.length - 1
   const endMinus = end - 1
   const slashInPreEnd = endMinus > 0 && topic.charCodeAt(endMinus) !== 47
-  if (topic.length === 0) { // [MQTT-3.8.3-3]
-    return new Error('impossible to ' + message + ' to an empty topic')
-  }
+
   for (let i = 0; i < topic.length; i++) {
     switch (topic.charCodeAt(i)) {
       case 35: { // #