diff --git a/lib/parser.js b/lib/parser.js
index be39d9c46..c486219f6 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -39,7 +39,7 @@ exports.encodePacket = function (packet) {
 
   // data fragment is optional
   if (undefined !== packet.data) {
-    encoded += packet.data;
+    encoded += String(packet.data);
   }
 
   return '' + encoded;