diff --git a/lib/transport.js b/lib/transport.js
index aee1bc8..dcc4844 100644
--- a/lib/transport.js
+++ b/lib/transport.js
@@ -1,5 +1,7 @@
 "use strict";
 
+const MAX_SMS_LENGTH = 160;
+
 const url = require('url');
 const request = require('request');
 const uuidv4 = require('uuid/v4');
@@ -20,8 +22,8 @@ function _send(destinationNumber, msg, handlerIMSI) {
     if (msg.length > 160) {
         logger.info('Splitting message');
 
-        const newMsg = msg.slice(0, 160);
-        const remainingMsg = msg.slice(160);
+        const newMsg = msg.slice(0, MAX_SMS_LENGTH);
+        const remainingMsg = msg.slice(MAX_SMS_LENGTH);
 
         _send(destinationNumber, newMsg, handlerIMSI);
         setTimeout(() => {