diff --git a/senlinclient/tests/unit/v1/test_cluster.py b/senlinclient/tests/unit/v1/test_cluster.py
index 239533a0..9b5f0b1a 100644
--- a/senlinclient/tests/unit/v1/test_cluster.py
+++ b/senlinclient/tests/unit/v1/test_cluster.py
@@ -273,6 +273,9 @@ class TestClusterUpdate(TestCluster):
             "nk1": "nv1",
             "nk2": "nv2",
         },
+        "config": {
+            "cluster.stop_node_before_delete": "true",
+        },
         "name": 'new_cluster',
         "profile_id": 'new_profile',
         "profile_only": False,
@@ -314,6 +317,7 @@ class TestClusterUpdate(TestCluster):
 
     def test_cluster_update_defaults(self):
         arglist = ['--name', 'new_cluster', '--metadata', 'nk1=nv1;nk2=nv2',
+                   '--config', 'cluster.stop_node_before_delete=true',
                    '--profile', 'new_profile', '--timeout', '30', '45edadcb']
         parsed_args = self.check_parser(self.cmd, arglist, [])
         self.cmd.take_action(parsed_args)
diff --git a/senlinclient/v1/cluster.py b/senlinclient/v1/cluster.py
index c37d617c..867a6cda 100644
--- a/senlinclient/v1/cluster.py
+++ b/senlinclient/v1/cluster.py
@@ -243,9 +243,11 @@ class UpdateCluster(command.ShowOne):
         parser.add_argument(
             '--config',
             metavar='<"key1=value1;key2=value2...">',
-            help=_('s of the cluster. Default to {}. '
+            help=_('Configuration of the cluster. '
                    'This can be specified multiple times, or once with '
-                   'key-value pairs separated by a semicolon.'),
+                   'key-value pairs separated by a semicolon. '
+                   'Any existing configuration values on the cluster are '
+                   'wiped out when using this option.'),
             action='append'
         )
         parser.add_argument(
@@ -303,6 +305,7 @@ class UpdateCluster(command.ShowOne):
                 strict=True,
             ),
             'metadata': senlin_utils.format_parameters(parsed_args.metadata),
+            'config': senlin_utils.format_parameters(parsed_args.config),
             'timeout': parsed_args.timeout,
         }