diff --git a/magnumclient/tests/v1/test_certificates_shell.py b/magnumclient/tests/v1/test_certificates_shell.py
index c34b9b42..3d79eee6 100644
--- a/magnumclient/tests/v1/test_certificates_shell.py
+++ b/magnumclient/tests/v1/test_certificates_shell.py
@@ -27,7 +27,7 @@ class ShellTest(shell_test_base.TestCommandLineArgument):
         mockbay.status = "CREATE_COMPLETE"
         mock_bay_get.return_value = mockbay
         self._test_arg_success('ca-show '
-                               'xxx')
+                               '--bay xxx')
         self.assertTrue(mock_cert_get.called)
 
     @mock.patch('os.path.isfile')
@@ -44,8 +44,8 @@ class ShellTest(shell_test_base.TestCommandLineArgument):
         file_mock = mock.mock_open(read_data=fake_csr)
         with mock.patch.object(certificates_shell, 'open', file_mock):
             self._test_arg_success('ca-sign '
-                                   'xxx '
-                                   'path/csr.pem')
+                                   '--csr path/csr.pem '
+                                   '--bay xxx')
             self.assertTrue(mock_cert_create.called)
 
     @mock.patch('os.path.isfile')
@@ -62,8 +62,8 @@ class ShellTest(shell_test_base.TestCommandLineArgument):
         file_mock = mock.mock_open(read_data=fake_csr)
         with mock.patch.object(certificates_shell, 'open', file_mock):
             self._test_arg_success('ca-sign '
-                                   'xxx '
-                                   'path/csr.pem')
+                                   '--csr path/csr.pem '
+                                   '--bay xxx')
             mock_isfile.assert_called_once_with('path/csr.pem')
             self.assertFalse(file_mock.called)
             self.assertFalse(mock_cert_create.called)
diff --git a/magnumclient/v1/certificates_shell.py b/magnumclient/v1/certificates_shell.py
index 510232f0..092e62cd 100644
--- a/magnumclient/v1/certificates_shell.py
+++ b/magnumclient/v1/certificates_shell.py
@@ -21,7 +21,8 @@ def _show_cert(certificate):
     print(certificate.pem)
 
 
-@utils.arg('bay',
+@utils.arg('--bay',
+           required=True,
            metavar='<bay>',
            help='ID or name of the bay.')
 def do_ca_show(cs, args):
@@ -35,12 +36,13 @@ def do_ca_show(cs, args):
     _show_cert(cert)
 
 
-@utils.arg('bay',
-           metavar='<bay>',
-           help='ID or name of the bay.')
-@utils.arg('csr',
+@utils.arg('--csr',
            metavar='<csr>',
            help='File path of the csr file to send to Magnum to get signed.')
+@utils.arg('--bay',
+           required=True,
+           metavar='<bay>',
+           help='ID or name of the bay.')
 def do_ca_sign(cs, args):
     """Generate the CA certificate for a bay."""
     bay = cs.bays.get(args.bay)