diff --git a/elasticsearch/client.py b/elasticsearch/client.py
index 0dd85e54..1d9b9cd6 100644
--- a/elasticsearch/client.py
+++ b/elasticsearch/client.py
@@ -83,7 +83,7 @@ class Elasticsearch(object):
     Elasticsearch low-level client. Provides a straightforward mapping from
     Python to ES REST endpoints.
     """
-    def __init__(self, hosts=None, **kwargs):
+    def __init__(self, hosts=None, transport_class=Transport, **kwargs):
         """
         :arg hosts: list of nodes we should connect to. Node should be a
             dictionary ({"host": "localhost", "port": 9200}), the entire dictionary
@@ -92,11 +92,13 @@ class Elasticsearch(object):
             translated to a dictionary automatically.  If no value is given the
             :class:`~elasticsearch.Connection` class defaults will be used.
 
+        :arg transport_class: :class:`~elasticsearch.Transport` subclass to use.
+
         :arg kwargs: any additional arguments will be passed on to the
             :class:`~elasticsearch.Transport` class and, subsequently, to the
             :class:`~elasticsearch.Connection` instances.
         """
-        self.transport = Transport(_normalize_hosts(hosts), **kwargs)
+        self.transport = transport_class(_normalize_hosts(hosts), **kwargs)
 
         # namespaced clients for compatibility with API names
         self.indices = InidicesClient(self)
diff --git a/test_elasticsearch/test_cases.py b/test_elasticsearch/test_cases.py
new file mode 100644
index 00000000..ffeb5a81
--- /dev/null
+++ b/test_elasticsearch/test_cases.py
@@ -0,0 +1,47 @@
+from unittest import TestCase
+from collections import defaultdict
+
+from elasticsearch import Elasticsearch
+
+class DummyTransport(object):
+    def __init__(self, hosts, responses=None, **kwargs):
+        self.responses = responses
+        self.call_count = 0
+        self.calls = defaultdict(list)
+
+    def perform_request(self, method, url, params=None, body=None):
+        resp = 200, {}
+        if self.responses:
+            resp = self.responses[self.call_count]
+        self.call_count += 1
+        self.calls[(method, url)].append((params, body))
+        return resp
+
+
+class ElasticsearchTestCase(TestCase):
+    def setUp(self):
+        super(ElasticsearchTestCase, self).setUp()
+        self.client = Elasticsearch(transport_class=DummyTransport)
+
+    def assert_call_count_equals(self, count):
+        self.assertEquals(count, self.client.transport.call_count)
+
+    def assert_url_called(self, method, url, count=1):
+        self.assertIn((method, url), self.client.transport.calls)
+        calls = self.client.transport.calls[(method, url)]
+        self.assertEquals(count, len(calls))
+        return calls
+
+
+class TestElasticsearchTestCase(ElasticsearchTestCase):
+    def test_our_transport_used(self):
+        self.assertIsInstance(self.client.transport, DummyTransport)
+
+    def test_start_with_0_call(self):
+        self.assert_call_count_equals(0)
+
+    def test_each_call_is_recorded(self):
+        self.client.transport.perform_request('GET', '/')
+        self.client.transport.perform_request('DELETE', '/42', params={}, body='body')
+        self.assert_call_count_equals(2)
+        self.assertEquals([({}, 'body')], self.assert_url_called('DELETE', '/42', 1))