diff --git a/Changelog.rst b/Changelog.rst
index 4363663e..952df062 100644
--- a/Changelog.rst
+++ b/Changelog.rst
@@ -8,6 +8,8 @@ Changelog
 
 Version compatible with elasticsearch 5.0
 
+ * added ``headers`` arg to connections to support custom http headers
+
 2.3.0 (2016-02-29)
 ------------------
 
diff --git a/elasticsearch/connection/http_requests.py b/elasticsearch/connection/http_requests.py
index 99da09f3..2ca7002a 100644
--- a/elasticsearch/connection/http_requests.py
+++ b/elasticsearch/connection/http_requests.py
@@ -24,15 +24,17 @@ class RequestsHttpConnection(Connection):
         certificate, or cert only if using client_key
     :arg client_key: path to the file containing the private key if using
         separate cert and key files (client_cert will contain only the cert)
+    :arg headers: any custom http headers to be add to requests
     """
     def __init__(self, host='localhost', port=9200, http_auth=None,
         use_ssl=False, verify_certs=False, ca_certs=None, client_cert=None,
-        client_key=None, **kwargs):
+        client_key=None, headers=None, **kwargs):
         if not REQUESTS_AVAILABLE:
             raise ImproperlyConfigured("Please install requests to use RequestsHttpConnection.")
 
         super(RequestsHttpConnection, self).__init__(host=host, port=port, **kwargs)
-        self.session = requests.session()
+        self.session = requests.Session()
+        self.session.headers = headers
         if http_auth is not None:
             if isinstance(http_auth, (tuple, list)):
                 http_auth = tuple(http_auth)
diff --git a/elasticsearch/connection/http_urllib3.py b/elasticsearch/connection/http_urllib3.py
index 866635f4..31857383 100644
--- a/elasticsearch/connection/http_urllib3.py
+++ b/elasticsearch/connection/http_urllib3.py
@@ -33,14 +33,16 @@ class Urllib3HttpConnection(Connection):
     :arg ssl_assert_fingerprint: verify the supplied certificate fingerprint if not `None`
     :arg maxsize: the maximum number of connections which will be kept open to
         this host.
+    :arg headers: any custom http headers to be add to requests
     """
     def __init__(self, host='localhost', port=9200, http_auth=None,
             use_ssl=False, verify_certs=False, ca_certs=None, client_cert=None,
             client_key=None, ssl_version=None, ssl_assert_hostname=None,
-            ssl_assert_fingerprint=None, maxsize=10, **kwargs):
+            ssl_assert_fingerprint=None, maxsize=10, headers=None, **kwargs):
 
         super(Urllib3HttpConnection, self).__init__(host=host, port=port, use_ssl=use_ssl, **kwargs)
-        self.headers = urllib3.make_headers(keep_alive=True)
+        self.headers = headers.copy() if headers else {}
+        self.headers.update(urllib3.make_headers(keep_alive=True))
         if http_auth is not None:
             if isinstance(http_auth, (tuple, list)):
                 http_auth = ':'.join(http_auth)