diff --git a/lib/handlers/validations.js b/lib/handlers/validations.js
index 16d9922b..61cbe901 100644
--- a/lib/handlers/validations.js
+++ b/lib/handlers/validations.js
@@ -1,13 +1,17 @@
 'use strict'
 
 function validateTopic (topic, message) {
-  var end = topic.length - 1
-  var endMinus = end - 1
-  var slashInPreEnd = endMinus > 0 && topic.charCodeAt(endMinus) !== 47
-  if (topic.length === 0) {
+  var tlen = topic.length
+
+  if (tlen === 0) {
     return new Error('impossible to ' + message + ' to an empty topic')
   }
-  for (var i = 0; i < topic.length; i++) {
+
+  var end = tlen - 1
+  var endMinus = end - 1
+  var slashInPreEnd = endMinus > 0 && topic.charCodeAt(endMinus) !== 47
+
+  for (var i = 0; i < tlen; i++) {
     switch (topic.charCodeAt(i)) {
       case 35:
         var notAtTheEnd = i !== end