diff --git a/lib/client.js b/lib/client.js
index ebd9cf1..fbd15ff 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -68,7 +68,7 @@ Client.prototype.call = function(options, callback, id){
         path: this.path,
         headers:{
             'content-type':(this.method=='POST') ? 'application/x-www-form-urlencoded' :'application/json',
-            'content-length':(requestData).length
+            'content-length':Buffer.byteLength(requestData)
         }
     };
     if(this.authNeeded){
@@ -122,4 +122,4 @@ Client.prototype.call = function(options, callback, id){
         request.end(requestData);
  
 };
-module.exports = Client;
\ No newline at end of file
+module.exports = Client;