diff --git a/blazarclient/tests/v1/shell_commands/test_leases.py b/blazarclient/tests/v1/shell_commands/test_leases.py
index a623445..97be1a9 100644
--- a/blazarclient/tests/v1/shell_commands/test_leases.py
+++ b/blazarclient/tests/v1/shell_commands/test_leases.py
@@ -114,3 +114,62 @@ class CreateLeaseTestCase(tests.TestCase):
         self.assertRaises(exception.DuplicatedLeaseParameters,
                           self.cl.args2body,
                           args)
+
+
+class UpdateLeaseTestCase(tests.TestCase):
+
+    def setUp(self):
+        super(UpdateLeaseTestCase, self).setUp()
+        self.cl = leases.UpdateLease(shell.BlazarShell(), mock.Mock())
+
+    def test_args2body_time_params(self):
+        args = argparse.Namespace(
+            name=None,
+            prolong_for='1h',
+            reduce_by=None,
+            end_date=None,
+            defer_by=None,
+            advance_by=None,
+            start_date=None,
+            reservation=None
+        )
+        expected = {
+            'prolong_for': '1h',
+        }
+
+        self.assertDictEqual(self.cl.args2body(args), expected)
+
+    def test_args2body_reservation_params(self):
+        args = argparse.Namespace(
+            name=None,
+            prolong_for=None,
+            reduce_by=None,
+            end_date=None,
+            defer_by=None,
+            advance_by=None,
+            start_date=None,
+            reservation=[
+                'id=798379a6-194c-45dc-ba34-1b5171d5552f,'
+                'max=3,'
+                'hypervisor_properties='
+                '["and", [">=", "$vcpus", "4"], '
+                '[">=", "$memory_mb", "8192"]],'
+                'resource_properties='
+                '["==", "$extra_key", "extra_value"]'
+            ]
+        )
+        expected = {
+            'reservations': [
+                {
+                    'id': '798379a6-194c-45dc-ba34-1b5171d5552f',
+                    'max': 3,
+                    'hypervisor_properties':
+                        '["and", [">=", "$vcpus", "4"], '
+                        '[">=", "$memory_mb", "8192"]]',
+                    'resource_properties':
+                        '["==", "$extra_key", "extra_value"]'
+                }
+            ]
+        }
+
+        self.assertDictEqual(self.cl.args2body(args), expected)
diff --git a/blazarclient/v1/leases.py b/blazarclient/v1/leases.py
index bae58a6..80b647b 100644
--- a/blazarclient/v1/leases.py
+++ b/blazarclient/v1/leases.py
@@ -38,7 +38,8 @@ class LeaseClientManager(base.BaseClientManager):
         return self._get('/leases/%s' % lease_id, 'lease')
 
     def update(self, lease_id, name=None, prolong_for=None, reduce_by=None,
-               end_date=None, advance_by=None, defer_by=None, start_date=None):
+               end_date=None, advance_by=None, defer_by=None, start_date=None,
+               reservations=None):
         """Update attributes of the lease."""
         values = {}
         if name:
@@ -72,6 +73,9 @@ class LeaseClientManager(base.BaseClientManager):
                                      lease_start_date_change,
                                      defer_by is not None)
 
+        if reservations:
+            values['reservations'] = reservations
+
         if not values:
             return _('No values to update passed.')
         return self._update('/leases/%s' % lease_id, values,
diff --git a/blazarclient/v1/shell_commands/leases.py b/blazarclient/v1/shell_commands/leases.py
index fe7346c..c06f2ae 100644
--- a/blazarclient/v1/shell_commands/leases.py
+++ b/blazarclient/v1/shell_commands/leases.py
@@ -286,6 +286,14 @@ class UpdateLease(command.UpdateCommand):
             help='New name for the lease',
             default=None
         )
+        parser.add_argument(
+            '--reservation',
+            metavar="<key=value>",
+            action='append',
+            help='Reservation values to update. The reservation must be '
+                 'selected with the id=<reservation-id> key-value pair.',
+            default=None)
+
         #prolong-for and reduce_by are mutually exclusive
         group = parser.add_mutually_exclusive_group()
         group.add_argument(
@@ -343,6 +351,44 @@ class UpdateLease(command.UpdateCommand):
             params['advance_by'] = parsed_args.advance_by
         if parsed_args.start_date:
             params['start_date'] = parsed_args.start_date
+        if parsed_args.reservation:
+            keys = [
+                # General keys
+                'id',
+                # Keys for host reservation
+                'min', 'max', 'hypervisor_properties', 'resource_properties',
+                # Keys for instance reservation (update of instance reservation
+                # is NOT yet supported)
+            ]
+            params['reservations'] = []
+            reservations = []
+            for res_str in parsed_args.reservation:
+                err_msg = ("Invalid reservation argument '%s'. "
+                           "Reservation arguments must be of the form "
+                           "--reservation <key=value>" % res_str)
+                res_info = {}
+                prog = re.compile('^(?:(.*),)?(%s)=(.*)$' % '|'.join(keys))
+
+                def parse_params(params):
+                    match = prog.search(params)
+                    if match:
+                        k, v = match.group(2, 3)
+                        if strutils.is_int_like(v):
+                            v = int(v)
+                        res_info[k] = v
+                        if match.group(1) is not None:
+                            parse_params(match.group(1))
+
+                parse_params(res_str)
+                if res_info:
+                    if 'id' not in res_info:
+                        raise exception.IncorrectLease(
+                            'The key-value pair id=<reservation_id> is '
+                            'required for the --reservation argument')
+                    reservations.append(res_info)
+            if not reservations:
+                raise exception.IncorrectLease(err_msg)
+            params['reservations'] = reservations
         return params