diff --git a/tempest/api/network/admin/test_negative_quotas.py b/tempest/api/network/admin/test_negative_quotas.py
index 190d9e3..614dfcf 100644
--- a/tempest/api/network/admin/test_negative_quotas.py
+++ b/tempest/api/network/admin/test_negative_quotas.py
@@ -45,11 +45,16 @@
         super(QuotasNegativeTest, self).setUp()
         name = data_utils.rand_name('test_project_')
         description = data_utils.rand_name('desc_')
-        self.project = identity.identity_utils(self.os_admin).create_project(
+        self.creds_client = identity.identity_utils(self.os_admin)
+        self.project = self.creds_client.create_project(
             name=name, description=description)
         self.addCleanup(identity.identity_utils(self.os_admin).delete_project,
                         self.project['id'])
 
+    def tearDown(self):
+        super(QuotasNegativeTest, self).tearDown()
+        self.credentials_provider.cleanup_default_secgroup(self.project['id'])
+
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('644f4e1b-1bf9-4af0-9fd8-eb56ac0f51cf')
     def test_network_quota_exceeding(self):
diff --git a/tempest/lib/common/dynamic_creds.py b/tempest/lib/common/dynamic_creds.py
index 3b17af2..32dea44 100644
--- a/tempest/lib/common/dynamic_creds.py
+++ b/tempest/lib/common/dynamic_creds.py
@@ -518,7 +518,7 @@
             LOG.warning('network with name: %s not found for delete',
                         network_name)
 
-    def _cleanup_default_secgroup(self, tenant):
+    def cleanup_default_secgroup(self, tenant):
         nsg_client = self.security_groups_admin_client
         resp_body = nsg_client.list_security_groups(tenant_id=tenant,
                                                     name="default")
@@ -572,13 +572,13 @@
                 LOG.warning("user with name: %s not found for delete",
                             creds.username)
             # NOTE(zhufl): Only when neutron's security_group ext is
-            # enabled, _cleanup_default_secgroup will not raise error. But
+            # enabled, cleanup_default_secgroup will not raise error. But
             # here cannot use test_utils.is_extension_enabled for it will cause
             # "circular dependency". So here just use try...except to
             # ensure tenant deletion without big changes.
             try:
                 if self.neutron_available:
-                    self._cleanup_default_secgroup(creds.tenant_id)
+                    self.cleanup_default_secgroup(creds.tenant_id)
             except lib_exc.NotFound:
                 LOG.warning("failed to cleanup tenant %s's secgroup",
                             creds.tenant_name)