diff --git a/elasticsearch/serializer.py b/elasticsearch/serializer.py
index 506c91e9..808db714 100644
--- a/elasticsearch/serializer.py
+++ b/elasticsearch/serializer.py
@@ -29,7 +29,7 @@ class JSONSerializer(object):
             return data.isoformat()
         elif isinstance(data, Decimal):
             return float(data)
-        elif isinstance(data, uuid.UUID): 
+        elif isinstance(data, uuid.UUID):
             return str(data)
         raise TypeError("Unable to serialize %r (type: %s)" % (data, type(data)))
 
@@ -45,7 +45,7 @@ class JSONSerializer(object):
             return data
 
         try:
-            return json.dumps(data, default=self.default)
+            return json.dumps(data, default=self.default, ensure_ascii=False)
         except (ValueError, TypeError) as e:
             raise SerializationError(data, e)