diff --git a/lib/restler.js b/lib/restler.js
index bf6cc57..6807268 100644
--- a/lib/restler.js
+++ b/lib/restler.js
@@ -63,12 +63,15 @@ function Request(uri, options) {
         console.log("Building multipart request without Content-Length header, please specify all file sizes");
     }
   } else {
-    if (typeof this.options.data == 'object') {
+    if (this.options.data instanceof Buffer) {
+      this.options.data = new Buffer(this.options.data.toString(), this.options.encoding || 'utf8');
+    }
+    else if (typeof this.options.data == 'object') {
       this.options.data = qs.stringify(this.options.data);
       this.headers['Content-Type'] = 'application/x-www-form-urlencoded';
       this.headers['Content-Length'] = this.options.data.length;
     }
-    if(typeof this.options.data == 'string') {
+    else if(typeof this.options.data == 'string') {
       var buffer = new Buffer(this.options.data, this.options.encoding || 'utf8');
       this.options.data = buffer;
       this.headers['Content-Length'] = buffer.length;
@@ -229,7 +232,6 @@ mixin(Request.prototype, {
   },
   run: function() {
     var self = this;
-    
     if (this.options.multipart) {
       multipart.write(this.request, this.options.data, function() {
         self.request.end();
@@ -368,12 +370,14 @@ var parsers = {
   },
   json: function(data, callback) {
     if (data && data.length) {
+      var json = null, 
+          err = null;
       try {
-        callback(null, JSON.parse(data));
-      } catch (err) {
+        json = JSON.parse(data);
+      }  catch (err) {
         err.message = 'Failed to parse JSON body: ' + err.message;
-        callback(err, null);
       }
+      callback(err, json);
     } else {
       callback(null, null);
     }
@@ -470,6 +474,16 @@ mixin(Service.prototype, {
   },
   _withDefaults: function(options) {
     var o = mixin({}, this.defaults);
+    if( options ) {
+      if(o.headers && options.headers) {
+        mixin(o.headers, options.headers);
+        delete options.headers;
+      }
+      if(o.query && options.query) {
+        mixin(o.query, options.query);
+        delete options.query;
+      }
+    }
     return mixin(o, options);
   }
 });