diff --git a/lib/Serializer.js b/lib/Serializer.js
index a2fae9148..5bb84adfb 100644
--- a/lib/Serializer.js
+++ b/lib/Serializer.js
@@ -49,7 +49,10 @@ class Serializer {
     const keys = Object.keys(object)
     for (var i = 0, len = keys.length; i < len; i++) {
       var key = keys[i]
-      if (Array.isArray(object[key]) === true) {
+      // elasticsearch will complain for keys without a value
+      if (object[key] === undefined) {
+        delete object[key]
+      } else if (Array.isArray(object[key]) === true) {
         object[key] = object[key].join(',')
       }
     }
diff --git a/lib/Transport.js b/lib/Transport.js
index 22fe090db..eec669d3f 100644
--- a/lib/Transport.js
+++ b/lib/Transport.js
@@ -34,10 +34,21 @@ class Transport {
   }
 
   request (params, options, callback) {
+    options = options || {}
     if (typeof options === 'function') {
       callback = options
       options = {}
     }
+
+    // promises support
+    if (callback == null) {
+      return new Promise((resolve, reject) => {
+        this.request(params, options, (err, result) => {
+          err ? reject(err) : resolve(result)
+        })
+      })
+    }
+
     callback = once(callback)
     // TODO: return in the result the metadata
     const meta = {