diff --git a/AUTHORS b/AUTHORS
index 21cc61535..930e564f9 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -32,6 +32,7 @@ Kiall Mac Innes <kiall@managedit.ie>
 Kirill Shileev <kshileev@griddynamics.com>
 Lvov Maxim <mlvov@mirantis.com>
 Matt Dietz <matt.dietz@rackspace.com>
+Matt Stephenson <mattstep@mattstep.net>
 Nicholas Mistry <nmistry@gmail.com>
 Nikolay Sokolov <nsokolov@griddynamics.com>
 Pavel Shkitin <pshkitin@griddynamics.com>
diff --git a/novaclient/client.py b/novaclient/client.py
index 855494270..5c40fd7b3 100644
--- a/novaclient/client.py
+++ b/novaclient/client.py
@@ -82,6 +82,7 @@ class HTTPClient(httplib2.Http):
     def request(self, *args, **kwargs):
         kwargs.setdefault('headers', kwargs.get('headers', {}))
         kwargs['headers']['User-Agent'] = self.USER_AGENT
+        kwargs['headers']['Accept'] = 'application/json'
         if 'body' in kwargs:
             kwargs['headers']['Content-Type'] = 'application/json'
             kwargs['body'] = json.dumps(kwargs['body'])
diff --git a/tests/test_http.py b/tests/test_http.py
index 2d1db58cc..d7847cc2c 100644
--- a/tests/test_http.py
+++ b/tests/test_http.py
@@ -36,6 +36,7 @@ class ClientTest(utils.TestCase):
             headers = {"X-Auth-Token": "token",
                        "X-Auth-Project-Id": "project_id",
                        "User-Agent": cl.USER_AGENT,
+                       'Accept': 'application/json',
             }
             mock_request.assert_called_with("http://example.com/hi",
                                             "GET", headers=headers)
@@ -54,6 +55,7 @@ class ClientTest(utils.TestCase):
                 "X-Auth-Token": "token",
                 "X-Auth-Project-Id": "project_id",
                 "Content-Type": "application/json",
+                'Accept': 'application/json',
                 "User-Agent": cl.USER_AGENT
             }
             mock_request.assert_called_with("http://example.com/hi", "POST",
diff --git a/tests/v1_1/test_auth.py b/tests/v1_1/test_auth.py
index d179e497e..4bd68635b 100644
--- a/tests/v1_1/test_auth.py
+++ b/tests/v1_1/test_auth.py
@@ -55,6 +55,7 @@ class AuthenticateAgainstKeystoneTests(utils.TestCase):
             headers = {
                 'User-Agent': cs.client.USER_AGENT,
                 'Content-Type': 'application/json',
+                'Accept': 'application/json',
             }
             body = {
                 'auth': {
@@ -152,6 +153,7 @@ class AuthenticateAgainstKeystoneTests(utils.TestCase):
             headers = {
                 'User-Agent': cs.client.USER_AGENT,
                 'Content-Type': 'application/json',
+                'Accept': 'application/json',
             }
             body = {
                 'auth': {
@@ -244,6 +246,7 @@ class AuthenticationTests(utils.TestCase):
         def test_auth_call():
             cs.client.authenticate()
             headers = {
+                'Accept': 'application/json',
                 'X-Auth-User': 'username',
                 'X-Auth-Key': 'password',
                 'X-Auth-Project-Id': 'project_id',