diff --git a/karborclient/tests/unit/v1/test_quota_classes.py b/karborclient/tests/unit/v1/test_quota_classes.py
index d5d93b4..436a79e 100644
--- a/karborclient/tests/unit/v1/test_quota_classes.py
+++ b/karborclient/tests/unit/v1/test_quota_classes.py
@@ -30,6 +30,15 @@ class QuotaClassesTest(base.TestCaseShell):
             '/quota_classes/default',
             data={'quota_class': {'plans': 50}}, headers={})
 
+    @mock.patch('karborclient.common.http.HTTPClient.json_request')
+    def test_quota_class_update_with_none(self, mock_request):
+        mock_request.return_value = mock_request_return
+        cs.quota_classes.update('default', {'plans': None})
+        mock_request.assert_called_with(
+            'PUT',
+            '/quota_classes/default',
+            data={'quota_class': {'plans': 50}}, headers={})
+
     @mock.patch('karborclient.common.http.HTTPClient.json_request')
     def test_show_quota_class(self, mock_request):
         mock_request.return_value = mock_request_return
diff --git a/karborclient/tests/unit/v1/test_quotas.py b/karborclient/tests/unit/v1/test_quotas.py
index b3c7bbb..b695b24 100644
--- a/karborclient/tests/unit/v1/test_quotas.py
+++ b/karborclient/tests/unit/v1/test_quotas.py
@@ -30,6 +30,15 @@ class QuotasTest(base.TestCaseShell):
             '/quotas/{project_id}'.format(project_id=fakes.PROJECT_ID),
             data={'quota': {'plans': 50}}, headers={})
 
+    @mock.patch('karborclient.common.http.HTTPClient.json_request')
+    def test_quota_update_with_none(self, mock_request):
+        mock_request.return_value = mock_request_return
+        cs.quotas.update(fakes.PROJECT_ID, {'plans': None})
+        mock_request.assert_called_with(
+            'PUT',
+            '/quotas/{project_id}'.format(project_id=fakes.PROJECT_ID),
+            data={'quota': {'plans': 50}}, headers={})
+
     @mock.patch('karborclient.common.http.HTTPClient.json_request')
     def test_show_quota(self, mock_request):
         mock_request.return_value = mock_request_return
diff --git a/karborclient/v1/quota_classes.py b/karborclient/v1/quota_classes.py
index 1fffa2e..ca37d3b 100644
--- a/karborclient/v1/quota_classes.py
+++ b/karborclient/v1/quota_classes.py
@@ -26,6 +26,9 @@ class QuotaClassManager(base.ManagerWithFind):
 
     def update(self, class_name, data):
 
+        if "plans" in data and data["plans"] is None:
+            data["plans"] = 50
+
         body = {"quota_class": data}
 
         return self._update('/quota_classes/{class_name}'
diff --git a/karborclient/v1/quotas.py b/karborclient/v1/quotas.py
index f682e95..fc02eec 100644
--- a/karborclient/v1/quotas.py
+++ b/karborclient/v1/quotas.py
@@ -26,6 +26,9 @@ class QuotaManager(base.ManagerWithFind):
 
     def update(self, project_id, data):
 
+        if "plans" in data and data["plans"] is None:
+            data["plans"] = 50
+
         body = {"quota": data}
 
         return self._update('/quotas/{project_id}'
diff --git a/karborclient/v1/shell.py b/karborclient/v1/shell.py
index c128528..b4946df 100644
--- a/karborclient/v1/shell.py
+++ b/karborclient/v1/shell.py
@@ -1357,7 +1357,7 @@ def _quota_set_pretty_show(quotas):
     metavar='<plans>',
     type=int,
     default=None,
-    help='New value for the "plans" quota.')
+    help='New value for the "plans" quota. The default value is 50.')
 def do_quota_update(cs, args):
     """Update the quotas for a project (Admin only)."""
     project_id = args.tenant
@@ -1400,7 +1400,7 @@ def do_quota_class_show(cs, args):
     metavar='<plans>',
     type=int,
     default=None,
-    help='New value for the "plans" quota.')
+    help='New value for the "plans" quota. The default value is 50.')
 def do_quota_class_update(cs, args):
     """Update the quotas for a quota class (Admin only)."""
     class_name = args.class_name