diff --git a/index.js b/index.js
index 1919407..93b728e 100644
--- a/index.js
+++ b/index.js
@@ -11,7 +11,7 @@ var ini = require('ini');
 var config = ini.parse(fs.readFileSync(__dirname + '/config.ini', 'utf-8'));
 
 var keepalive_interval = 2 * 60 * 1000;
-
+var last_message_hash = '';
 var log_level = 'info';
 
 if (config.globals.log_level) {
@@ -56,6 +56,14 @@ function onPm(data) {
     logger.verbose('onPM()', {data: data});
     
     var message = striptags(data.message);
+    
+    var message_hash = data.sender + ': ' + data.message;
+    if (message_hash == last_message_hash) {
+        logger.verbose('Ignoring duplicate message');
+        return;
+    }
+    last_message_hash = message_hash;
+    
     var greeting_prefix = "Pesan anda telah diterima dan akan segera diproses:";
     if (config.globals.greeting_prefix) {
         greeting_prefix = config.globals.greeting_prefix;