diff --git a/elasticsearch/connection/http_urllib3.py b/elasticsearch/connection/http_urllib3.py
index 14705dad..22f2795b 100644
--- a/elasticsearch/connection/http_urllib3.py
+++ b/elasticsearch/connection/http_urllib3.py
@@ -40,10 +40,7 @@ class Urllib3HttpConnection(Connection):
             kw = {}
             if timeout:
                 kw['timeout'] = timeout
-            headers = self.headers.copy()
-            if body:
-                headers['content-length'] = str(len(body))
-            response = self.pool.urlopen(method, url, body, retries=False, headers=headers, **kw)
+            response = self.pool.urlopen(method, url, body, retries=False, headers=self.headers, **kw)
             duration = time.time() - start
             raw_data = response.data.decode('utf-8')
         except Exception as e:
diff --git a/test_elasticsearch/test_connection.py b/test_elasticsearch/test_connection.py
index d9866353..e1448a2a 100644
--- a/test_elasticsearch/test_connection.py
+++ b/test_elasticsearch/test_connection.py
@@ -53,14 +53,6 @@ class TestUrllib3Connection(TestCase):
         con = Urllib3HttpConnection()
         self.assertIsInstance(con.pool, urllib3.HTTPConnectionPool)
 
-    def test_content_length_gets_set(self):
-        con = Urllib3HttpConnection()
-        m = con.pool.urlopen = Mock()
-        m.return_value.status = 200
-
-        con.perform_request('PUT', '/', body='0123456789'.encode('utf-8'))
-        m.assert_called_once_with('PUT', '/', '0123456789'.encode('utf-8'), headers={'content-length': '10'}, retries=False)
-
 class TestRequestsConnection(TestCase):
     def _get_mock_connection(self, connection_params={}, status_code=200, response_body='{}'):
         con = RequestsHttpConnection(**connection_params)