diff --git a/examples/keystone_auth.py b/examples/keystone_auth.py
index c5f90fb8..16a5b8cd 100644
--- a/examples/keystone_auth.py
+++ b/examples/keystone_auth.py
@@ -33,7 +33,7 @@ def create_post_delete(queue_name, messages):
             {'backend': 'keystone',
              'options': {'os_username': 'zaqar',
                          'os_password': 'zaqar',
-                         'project_id': 'ccad479c402f43a2994f6e372ab3f8fe',
+                         'os_project_id': 'ccad479c402f43a2994f6e372ab3f8fe',
                          'os_project_name': '',
                          'os_auth_url': 'http://127.0.0.1:5000/v2.0/',
                          'insecure': ''}
diff --git a/examples/signed_url_auth.py b/examples/signed_url_auth.py
index 5d028c35..0239f526 100644
--- a/examples/signed_url_auth.py
+++ b/examples/signed_url_auth.py
@@ -34,7 +34,7 @@ def create_post_delete(queue_name, messages):
                          'expires': '',
                          'methods': ['GET', 'PATCH', 'POST', 'PUT'],
                          'paths': ['/v2/queues/beijing/claims'],
-                         'project_id': '2887aabf368046a3bb0070f1c0413470'}
+                         'os_project_id': '2887aabf368046a3bb0070f1c0413470'}
              }
             }
     cli = client.Client(URL, conf=conf)
diff --git a/tests/unit/transport/test_request.py b/tests/unit/transport/test_request.py
index 23318041..53f11470 100644
--- a/tests/unit/transport/test_request.py
+++ b/tests/unit/transport/test_request.py
@@ -27,7 +27,7 @@ class TestRequest(base.TestBase):
     def test_request_project_id(self):
         auth_opts = {
             'options': {
-                'project_id': 'my-project'
+                'os_project_id': 'my-project'
             }
         }
         auth_opts.update({'backend': 'noauth'})
diff --git a/tests/unit/transport/test_ws.py b/tests/unit/transport/test_ws.py
index 6e036649..aad30de5 100644
--- a/tests/unit/transport/test_ws.py
+++ b/tests/unit/transport/test_ws.py
@@ -25,7 +25,7 @@ class TestWsTransport(base.TestBase):
         os_opts = {
             'os_auth_token': 'FAKE_TOKEN',
             'os_auth_url': 'http://127.0.0.0:5000/v3',
-            'project_id': 'admin',
+            'os_project_id': 'admin',
             'os_service_type': 'messaging-websocket',
         }
         auth_opts = {'backend': 'keystone',
diff --git a/zaqarclient/tests/base.py b/zaqarclient/tests/base.py
index c23affb2..173b22e8 100644
--- a/zaqarclient/tests/base.py
+++ b/zaqarclient/tests/base.py
@@ -37,7 +37,7 @@ class TestBase(testtools.TestCase):
             'auth_opts': {
                 'backend': 'noauth',
                 'options': {
-                    'project_id': 'my-project'
+                    'os_project_id': 'my-project'
                 }
             }
         }
@@ -90,7 +90,7 @@ class TestBase(testtools.TestCase):
         options = {'os_username': self.creds['username'],
                    'os_password': self.creds['password'],
                    'os_project_name': self.creds['project_name'],
-                   'project_id': '',
+                   'os_project_id': '',
                    'os_auth_url': auth_url}
 
         self.conf['auth_opts'].setdefault('options', {}).update(options)
diff --git a/zaqarclient/tests/queues/queues.py b/zaqarclient/tests/queues/queues.py
index fb351f7e..88ca1d29 100644
--- a/zaqarclient/tests/queues/queues.py
+++ b/zaqarclient/tests/queues/queues.py
@@ -600,7 +600,7 @@ class QueuesV2QueueFunctionalTest(QueuesV1_1QueueFunctionalTest):
             'expires': signature['expires'],
             'methods': signature['methods'],
             'signature': signature['signature'],
-            'project_id': signature['project'],
+            'os_project_id': signature['project'],
         }
         auth_opts = {'backend': 'signed-url',
                      'options': opts}
diff --git a/zaqarclient/transport/request.py b/zaqarclient/transport/request.py
index cb698cd5..8a9821a2 100644
--- a/zaqarclient/transport/request.py
+++ b/zaqarclient/transport/request.py
@@ -45,7 +45,7 @@ def prepare_request(auth_opts=None, data=None, **kwargs):
     auth_backend = auth.get_backend(**(auth_opts or {}))
     req = auth_backend.authenticate(kwargs.get('api'), req)
 
-    project_id = auth_opts.get('options', {}).get('project_id', None)
+    project_id = auth_opts.get('options', {}).get('os_project_id', {})
 
     # Let's add project id header, only if it will have non-empty value.
     if project_id:
diff --git a/zaqarclient/transport/ws.py b/zaqarclient/transport/ws.py
index b55355a5..ab22d1ef 100644
--- a/zaqarclient/transport/ws.py
+++ b/zaqarclient/transport/ws.py
@@ -42,7 +42,7 @@ class WebsocketTransport(base.Transport):
                 'backend': 'keystone',
                 'options': {
                     'os_auth_token': ks.auth_token,
-                    'project_id': CONF.zaqar.project_id
+                    'os_project_id': CONF.zaqar.project_id
                 }
             }
         }
@@ -57,7 +57,7 @@ class WebsocketTransport(base.Transport):
     """
     def __init__(self, options):
         super(WebsocketTransport, self).__init__(options)
-        self._project_id = options['auth_opts']['options']['project_id']
+        self._project_id = options['auth_opts']['options']['os_project_id']
         self._token = options['auth_opts']['options']['os_auth_token']
         self._websocket_client_id = None
         self._ws = None