diff --git a/mistralclient/api/v2/executions.py b/mistralclient/api/v2/executions.py
index d158964b..5ac87b35 100644
--- a/mistralclient/api/v2/executions.py
+++ b/mistralclient/api/v2/executions.py
@@ -1,4 +1,5 @@
 # Copyright 2014 - Mirantis, Inc.
+# Copyright 2015 - StackStorm, Inc.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License");
 #    you may not use this file except in compliance with the License.
@@ -58,12 +59,17 @@ class ExecutionManager(base.ResourceManager):
     def create_direct_workflow(self, workflow_name, workflow_input, **params):
         return self.create(workflow_name, workflow_input, **params)
 
-    def update(self, id, state, description=None):
+    def update(self, id, state, description=None, env=None):
+        data = {}
+
         if state:
-            data = {'state': state}
+            data['state'] = state
 
         if description:
-            data = ({'description': description})
+            data['description'] = description
+
+        if env:
+            data['params'] = {'env': env}
 
         return self._update('/executions/%s' % id, data)
 
diff --git a/mistralclient/api/v2/tasks.py b/mistralclient/api/v2/tasks.py
index 25b1935c..3db91804 100644
--- a/mistralclient/api/v2/tasks.py
+++ b/mistralclient/api/v2/tasks.py
@@ -13,6 +13,8 @@
 #    See the License for the specific language governing permissions and
 #    limitations under the License.
 
+import json
+
 from mistralclient.api import base
 
 
@@ -36,7 +38,7 @@ class TaskManager(base.ResourceManager):
 
         return self._get('/tasks/%s' % id)
 
-    def rerun(self, task_ex_id, reset=True):
+    def rerun(self, task_ex_id, reset=True, env=None):
         url = '/tasks/%s' % task_ex_id
 
         body = {
@@ -45,4 +47,7 @@ class TaskManager(base.ResourceManager):
             'reset': reset
         }
 
+        if env:
+            body['env'] = json.dumps(env)
+
         return self._update(url, body)
diff --git a/mistralclient/commands/v2/environments.py b/mistralclient/commands/v2/environments.py
index 527adc3c..3a145c0d 100644
--- a/mistralclient/commands/v2/environments.py
+++ b/mistralclient/commands/v2/environments.py
@@ -18,7 +18,6 @@ import logging
 
 from cliff import command
 from cliff import show
-import yaml
 
 from mistralclient.commands.v2 import base
 from mistralclient import utils
@@ -89,17 +88,6 @@ def format(environment=None):
     return columns, data
 
 
-def load_file_content(f):
-    content = f.read()
-
-    try:
-        data = yaml.safe_load(content)
-    except Exception:
-        data = json.loads(content)
-
-    return data
-
-
 class List(base.MistralLister):
     """List all environments."""
 
@@ -146,7 +134,7 @@ class Create(show.ShowOne):
         return parser
 
     def take_action(self, parsed_args):
-        data = load_file_content(parsed_args.file)
+        data = utils.load_content(parsed_args.file.read())
 
         mistral_client = self.app.client_manager.workflow_engine
         environment = mistral_client.environments.create(**data)
@@ -190,7 +178,7 @@ class Update(show.ShowOne):
         return parser
 
     def take_action(self, parsed_args):
-        data = load_file_content(parsed_args.file)
+        data = utils.load_content(parsed_args.file.read())
 
         mistral_client = self.app.client_manager.workflow_engine
         environment = mistral_client.environments.update(**data)
diff --git a/mistralclient/commands/v2/executions.py b/mistralclient/commands/v2/executions.py
index cf23a0c0..c44dbe0f 100644
--- a/mistralclient/commands/v2/executions.py
+++ b/mistralclient/commands/v2/executions.py
@@ -1,4 +1,5 @@
 # Copyright 2014 - Mirantis, Inc.
+# Copyright 2015 - StackStorm, Inc.
 # All Rights Reserved
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -16,6 +17,7 @@
 
 import json
 import logging
+import os.path
 
 from cliff import command
 from cliff import show
@@ -225,15 +227,22 @@ class Update(show.ShowOne):
             help='Execution identifier'
         )
 
-        group = parser.add_mutually_exclusive_group(required=True)
-        group.add_argument(
+        parser.add_argument(
             '-s',
             '--state',
             dest='state',
             choices=['RUNNING', 'PAUSED', 'SUCCESS', 'ERROR'],
             help='Execution state'
         )
-        group.add_argument(
+
+        parser.add_argument(
+            '-e',
+            '--env',
+            dest='env',
+            help='Environment variables'
+        )
+
+        parser.add_argument(
             '-d',
             '--description',
             dest='description',
@@ -245,10 +254,18 @@ class Update(show.ShowOne):
     def take_action(self, parsed_args):
         mistral_client = self.app.client_manager.workflow_engine
 
+        env = (
+            utils.load_file(parsed_args.env)
+            if parsed_args.env and os.path.isfile(parsed_args.env)
+            else utils.load_content(parsed_args.env)
+        )
+
         execution = mistral_client.executions.update(
             parsed_args.id,
             parsed_args.state,
-            parsed_args.description)
+            description=parsed_args.description,
+            env=env
+        )
 
         return format(execution)
 
diff --git a/mistralclient/commands/v2/tasks.py b/mistralclient/commands/v2/tasks.py
index 5de21d09..207c4eba 100644
--- a/mistralclient/commands/v2/tasks.py
+++ b/mistralclient/commands/v2/tasks.py
@@ -17,11 +17,13 @@
 
 import json
 import logging
+import os.path
 
 from cliff import command
 from cliff import show
 
 from mistralclient.commands.v2 import base
+from mistralclient import utils
 
 LOG = logging.getLogger(__name__)
 
@@ -163,13 +165,28 @@ class Rerun(show.ShowOne):
                   'executions for with-items task')
         )
 
+        parser.add_argument(
+            '-e',
+            '--env',
+            dest='env',
+            help='Environment variables'
+        )
+
         return parser
 
     def take_action(self, parsed_args):
         mistral_client = self.app.client_manager.workflow_engine
+
+        env = (
+            utils.load_file(parsed_args.env)
+            if parsed_args.env and os.path.isfile(parsed_args.env)
+            else utils.load_content(parsed_args.env)
+        )
+
         execution = mistral_client.tasks.rerun(
             parsed_args.id,
-            reset=(not parsed_args.resume)
+            reset=(not parsed_args.resume),
+            env=env
         )
 
         return format(execution)
diff --git a/mistralclient/tests/unit/test_utils.py b/mistralclient/tests/unit/test_utils.py
new file mode 100644
index 00000000..8eb08e9e
--- /dev/null
+++ b/mistralclient/tests/unit/test_utils.py
@@ -0,0 +1,57 @@
+# Copyright 2015 - StackStorm, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+
+import json
+import os.path
+import tempfile
+import testtools
+import yaml
+
+from mistralclient import utils
+
+
+ENV_DICT = {'k1': 'abc', 'k2': 123, 'k3': True}
+ENV_STR = json.dumps(ENV_DICT)
+ENV_YAML = yaml.safe_dump(ENV_DICT, default_flow_style=False)
+
+
+class UtilityTest(testtools.TestCase):
+
+    def test_load_empty(self):
+        self.assertDictEqual(dict(), utils.load_content(None))
+        self.assertDictEqual(dict(), utils.load_content(''))
+        self.assertDictEqual(dict(), utils.load_content('{}'))
+        self.assertListEqual(list(), utils.load_content('[]'))
+
+    def test_load_json_content(self):
+        self.assertDictEqual(ENV_DICT, utils.load_content(ENV_STR))
+
+    def test_load_json_file(self):
+        with tempfile.NamedTemporaryFile() as f:
+            f.write(ENV_STR.encode('utf-8'))
+            f.flush()
+            file_path = os.path.abspath(f.name)
+
+            self.assertDictEqual(ENV_DICT, utils.load_file(file_path))
+
+    def test_load_yaml_content(self):
+        self.assertDictEqual(ENV_DICT, utils.load_content(ENV_YAML))
+
+    def test_load_yaml_file(self):
+        with tempfile.NamedTemporaryFile() as f:
+            f.write(ENV_YAML.encode('utf-8'))
+            f.flush()
+            file_path = os.path.abspath(f.name)
+
+            self.assertDictEqual(ENV_DICT, utils.load_file(file_path))
diff --git a/mistralclient/tests/unit/v2/test_cli_executions.py b/mistralclient/tests/unit/v2/test_cli_executions.py
index 2e81855e..391070a2 100644
--- a/mistralclient/tests/unit/v2/test_cli_executions.py
+++ b/mistralclient/tests/unit/v2/test_cli_executions.py
@@ -1,4 +1,5 @@
-# Copyright 2014 Mirantis, Inc.
+# Copyright 2014 - Mirantis, Inc.
+# Copyright 2015 - StackStorm, Inc.
 # All Rights Reserved
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -36,47 +37,95 @@ class TestCLIExecutionsV2(base.BaseCommandTest):
     def test_create_wf_input_string(self):
         self.client.executions.create.return_value = EXECUTION
 
-        result = self.call(execution_cmd.Create,
-                           app_args=['id', '{ "context": true }'])
+        result = self.call(
+            execution_cmd.Create,
+            app_args=['id', '{ "context": true }']
+        )
 
-        self.assertEqual(('123', 'some', '', 'RUNNING', None,
-                          '1', '1'), result[1])
+        self.assertEqual(
+            ('123', 'some', '', 'RUNNING', None, '1', '1'),
+            result[1]
+        )
 
     def test_create_wf_input_file(self):
         self.client.executions.create.return_value = EXECUTION
-        path = pkg.resource_filename('mistralclient',
-                                     'tests/unit/resources/ctx.json')
-        result = self.call(execution_cmd.Create,
-                           app_args=['id', path])
 
-        self.assertEqual(('123', 'some', '', 'RUNNING', None,
-                          '1', '1'), result[1])
+        path = pkg.resource_filename(
+            'mistralclient',
+            'tests/unit/resources/ctx.json'
+        )
+
+        result = self.call(
+            execution_cmd.Create,
+            app_args=['id', path]
+        )
+
+        self.assertEqual(
+            ('123', 'some', '', 'RUNNING', None, '1', '1'),
+            result[1]
+        )
 
     def test_create_with_description(self):
         self.client.executions.create.return_value = EXECUTION
 
-        result = self.call(execution_cmd.Create,
-                           app_args=['id', '{ "context": true }', '-d', ''])
+        result = self.call(
+            execution_cmd.Create,
+            app_args=['id', '{ "context": true }', '-d', '']
+        )
 
-        self.assertEqual(('123', 'some', '', 'RUNNING', None,
-                          '1', '1'), result[1])
+        self.assertEqual(
+            ('123', 'some', '', 'RUNNING', None, '1', '1'),
+            result[1]
+        )
 
-    def test_update(self):
+    def test_update_state(self):
         self.client.executions.update.return_value = EXECUTION
 
-        result = self.call(execution_cmd.Update,
-                           app_args=['id', '-s', 'SUCCESS'])
+        result = self.call(
+            execution_cmd.Update,
+            app_args=['id', '-s', 'SUCCESS']
+        )
 
-        self.assertEqual(('123', 'some', '', 'RUNNING', None,
-                          '1', '1'), result[1])
+        self.assertEqual(
+            ('123', 'some', '', 'RUNNING', None, '1', '1'),
+            result[1]
+        )
+
+    def test_resume_update_env(self):
+        self.client.executions.update.return_value = EXECUTION
+
+        result = self.call(
+            execution_cmd.Update,
+            app_args=['id', '-s', 'RUNNING', '--env', '{"k1": "foobar"}']
+        )
+
+        self.assertEqual(
+            ('123', 'some', '', 'RUNNING', None, '1', '1'),
+            result[1]
+        )
+
+    def test_update_description(self):
+        self.client.executions.update.return_value = EXECUTION
+
+        result = self.call(
+            execution_cmd.Update,
+            app_args=['id', '-d', 'foobar']
+        )
+
+        self.assertEqual(
+            ('123', 'some', '', 'RUNNING', None, '1', '1'),
+            result[1]
+        )
 
     def test_list(self):
         self.client.executions.list.return_value = (EXECUTION,)
 
         result = self.call(execution_cmd.List)
 
-        self.assertEqual([('123', 'some', '', 'RUNNING', None,
-                          '1', '1')], result[1])
+        self.assertEqual(
+            [('123', 'some', '', 'RUNNING', None, '1', '1')],
+            result[1]
+        )
 
     def test_list_with_pagination(self):
         self.client.executions.list.return_value = (EXECUTION,)
@@ -111,8 +160,10 @@ class TestCLIExecutionsV2(base.BaseCommandTest):
 
         result = self.call(execution_cmd.Get, app_args=['id'])
 
-        self.assertEqual(('123', 'some', '', 'RUNNING', None,
-                          '1', '1'), result[1])
+        self.assertEqual(
+            ('123', 'some', '', 'RUNNING', None, '1', '1'),
+            result[1]
+        )
 
     def test_delete(self):
         self.call(execution_cmd.Delete, app_args=['id'])
diff --git a/mistralclient/tests/unit/v2/test_cli_tasks.py b/mistralclient/tests/unit/v2/test_cli_tasks.py
index 6b76f5f7..8543c06c 100644
--- a/mistralclient/tests/unit/v2/test_cli_tasks.py
+++ b/mistralclient/tests/unit/v2/test_cli_tasks.py
@@ -1,4 +1,5 @@
-# Copyright 2014 Mirantis, Inc.
+# Copyright 2014 - Mirantis, Inc.
+# Copyright 2015 - StackStorm, Inc.
 # All Rights Reserved
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -101,3 +102,23 @@ class TestCLITasksV2(base.BaseCommandTest):
         result = self.call(task_cmd.Rerun, app_args=['id', '--resume'])
 
         self.assertEqual(EXPECTED_TASK_RESULT, result[1])
+
+    def test_rerun_update_env(self):
+        self.client.tasks.rerun.return_value = TASK
+
+        result = self.call(
+            task_cmd.Rerun,
+            app_args=['id', '--env', '{"k1": "foobar"}']
+        )
+
+        self.assertEqual(EXPECTED_TASK_RESULT, result[1])
+
+    def test_rerun_no_reset_update_env(self):
+        self.client.tasks.rerun.return_value = TASK
+
+        result = self.call(
+            task_cmd.Rerun,
+            app_args=['id', '--resume', '--env', '{"k1": "foobar"}']
+        )
+
+        self.assertEqual(EXPECTED_TASK_RESULT, result[1])
diff --git a/mistralclient/tests/unit/v2/test_executions.py b/mistralclient/tests/unit/v2/test_executions.py
index 02089293..2641e53e 100644
--- a/mistralclient/tests/unit/v2/test_executions.py
+++ b/mistralclient/tests/unit/v2/test_executions.py
@@ -1,4 +1,5 @@
 # Copyright 2014 - Mirantis, Inc.
+# Copyright 2015 - StackStorm, Inc.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License");
 #    you may not use this file except in compliance with the License.
@@ -48,12 +49,18 @@ class TestExecutionsV2(base.BaseClientV2Test):
             'input': json.dumps(EXEC['input']),
         }
 
-        ex = self.executions.create(EXEC['workflow_name'],
-                                    EXEC['input'])
+        ex = self.executions.create(
+            EXEC['workflow_name'],
+            EXEC['input']
+        )
 
         self.assertIsNotNone(ex)
-        self.assertEqual(executions.Execution(self.executions, EXEC).to_dict(),
-                         ex.to_dict())
+
+        self.assertEqual(
+            executions.Execution(self.executions, EXEC).to_dict(),
+            ex.to_dict()
+        )
+
         mock.assert_called_once_with(URL_TEMPLATE, json.dumps(body))
 
     @unittest2.expectedFailure
@@ -64,8 +71,10 @@ class TestExecutionsV2(base.BaseClientV2Test):
     @unittest2.expectedFailure
     def test_create_failure2(self):
         self.mock_http_post(content=EXEC)
-        self.executions.create(EXEC['workflow_name'],
-                               list('343', 'sdfsd'))
+        self.executions.create(
+            EXEC['workflow_name'],
+            list('343', 'sdfsd')
+        )
 
     def test_update(self):
         mock = self.mock_http_put(content=EXEC)
@@ -76,10 +85,43 @@ class TestExecutionsV2(base.BaseClientV2Test):
         ex = self.executions.update(EXEC['id'], EXEC['state'])
 
         self.assertIsNotNone(ex)
-        self.assertEqual(executions.Execution(self.executions, EXEC).to_dict(),
-                         ex.to_dict())
+
+        self.assertEqual(
+            executions.Execution(self.executions, EXEC).to_dict(),
+            ex.to_dict()
+        )
+
         mock.assert_called_once_with(
-            URL_TEMPLATE_ID % EXEC['id'], json.dumps(body))
+            URL_TEMPLATE_ID % EXEC['id'],
+            json.dumps(body)
+        )
+
+    def test_update_env(self):
+        mock = self.mock_http_put(content=EXEC)
+        body = {
+            'state': EXEC['state'],
+            'params': {
+                'env': {'k1': 'foobar'}
+            }
+        }
+
+        ex = self.executions.update(
+            EXEC['id'],
+            EXEC['state'],
+            env={'k1': 'foobar'}
+        )
+
+        self.assertIsNotNone(ex)
+
+        self.assertEqual(
+            executions.Execution(self.executions, EXEC).to_dict(),
+            ex.to_dict()
+        )
+
+        mock.assert_called_once_with(
+            URL_TEMPLATE_ID % EXEC['id'],
+            json.dumps(body)
+        )
 
     def test_list(self):
         mock = self.mock_http_get(content={'executions': [EXEC]})
@@ -116,8 +158,11 @@ class TestExecutionsV2(base.BaseClientV2Test):
 
         ex = self.executions.get(EXEC['id'])
 
-        self.assertEqual(executions.Execution(self.executions, EXEC).to_dict(),
-                         ex.to_dict())
+        self.assertEqual(
+            executions.Execution(self.executions, EXEC).to_dict(),
+            ex.to_dict()
+        )
+
         mock.assert_called_once_with(URL_TEMPLATE_ID % EXEC['id'])
 
     def test_delete(self):
diff --git a/mistralclient/tests/unit/v2/test_tasks.py b/mistralclient/tests/unit/v2/test_tasks.py
index 546b0e8c..d606b4c9 100644
--- a/mistralclient/tests/unit/v2/test_tasks.py
+++ b/mistralclient/tests/unit/v2/test_tasks.py
@@ -1,4 +1,5 @@
 # Copyright 2014 - Mirantis, Inc.
+# Copyright 2015 - StackStorm, Inc.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License");
 #    you may not use this file except in compliance with the License.
@@ -101,3 +102,25 @@ class TestTasksV2(base.BaseClientV2Test):
             },
             json.loads(mock.call_args[0][1])
         )
+
+    def test_rerun_update_env(self):
+        mock = self.mock_http_put(content=TASK)
+
+        task = self.tasks.rerun(TASK['id'], env={'k1': 'foobar'})
+
+        self.assertDictEqual(
+            tasks.Task(self.tasks, TASK).to_dict(),
+            task.to_dict()
+        )
+
+        self.assertEqual(1, mock.call_count)
+        self.assertEqual(URL_TEMPLATE_ID % TASK['id'], mock.call_args[0][0])
+        self.assertDictEqual(
+            {
+                'reset': True,
+                'state': 'RUNNING',
+                'id': TASK['id'],
+                'env': json.dumps({'k1': 'foobar'})
+            },
+            json.loads(mock.call_args[0][1])
+        )
diff --git a/mistralclient/utils.py b/mistralclient/utils.py
index 17b1485d..d143f9ba 100644
--- a/mistralclient/utils.py
+++ b/mistralclient/utils.py
@@ -1,4 +1,5 @@
 # Copyright 2015 - Huawei Technologies Co. Ltd
+# Copyright 2015 - StackStorm, Inc.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License");
 #    you may not use this file except in compliance with the License.
@@ -12,6 +13,10 @@
 #    See the License for the specific language governing permissions and
 #    limitations under the License.
 
+import json
+
+import yaml
+
 from mistralclient import exceptions
 
 
@@ -29,3 +34,20 @@ def do_action_on_many(action, resources, success_msg, error_msg):
 
     if failure_flag:
         raise exceptions.MistralClientException(error_msg)
+
+
+def load_content(content):
+    if content is None or content == '':
+        return dict()
+
+    try:
+        data = yaml.safe_load(content)
+    except Exception:
+        data = json.loads(content)
+
+    return data
+
+
+def load_file(path):
+    with open(path, 'r') as f:
+        return load_content(f.read())