diff --git a/tempest/api/compute/admin/test_quotas_negative.py b/tempest/api/compute/admin/test_quotas_negative.py
index d6aba5b..015e14d 100644
--- a/tempest/api/compute/admin/test_quotas_negative.py
+++ b/tempest/api/compute/admin/test_quotas_negative.py
@@ -40,6 +40,17 @@
         # tenant most of them should be skipped if we can't do that
         cls.demo_tenant_id = cls.client.tenant_id
 
+    def _update_quota(self, quota_item, quota_value):
+        quota_set = (self.adm_client.show_quota_set(self.demo_tenant_id)
+                     ['quota_set'])
+        default_quota_value = quota_set[quota_item]
+
+        self.adm_client.update_quota_set(self.demo_tenant_id,
+                                         force=True,
+                                         **{quota_item: quota_value})
+        self.addCleanup(self.adm_client.update_quota_set, self.demo_tenant_id,
+                        **{quota_item: default_quota_value})
+
     @test.attr(type=['negative'])
     @test.idempotent_id('733abfe8-166e-47bb-8363-23dbd7ff3476')
     def test_update_quota_normal_user(self):
@@ -54,17 +65,7 @@
     @test.idempotent_id('91058876-9947-4807-9f22-f6eb17140d9b')
     def test_create_server_when_cpu_quota_is_full(self):
         # Disallow server creation when tenant's vcpu quota is full
-        quota_set = (self.adm_client.show_quota_set(self.demo_tenant_id)
-                     ['quota_set'])
-        default_vcpu_quota = quota_set['cores']
-        vcpu_quota = 0  # Set the quota to zero to conserve resources
-
-        self.adm_client.update_quota_set(self.demo_tenant_id,
-                                         force=True,
-                                         cores=vcpu_quota)
-
-        self.addCleanup(self.adm_client.update_quota_set, self.demo_tenant_id,
-                        cores=default_vcpu_quota)
+        self._update_quota('cores', 0)
         self.assertRaises((lib_exc.Forbidden, lib_exc.OverLimit),
                           self.create_test_server)
 
@@ -72,17 +73,7 @@
     @test.idempotent_id('6fdd7012-584d-4327-a61c-49122e0d5864')
     def test_create_server_when_memory_quota_is_full(self):
         # Disallow server creation when tenant's memory quota is full
-        quota_set = (self.adm_client.show_quota_set(self.demo_tenant_id)
-                     ['quota_set'])
-        default_mem_quota = quota_set['ram']
-        mem_quota = 0  # Set the quota to zero to conserve resources
-
-        self.adm_client.update_quota_set(self.demo_tenant_id,
-                                         force=True,
-                                         ram=mem_quota)
-
-        self.addCleanup(self.adm_client.update_quota_set, self.demo_tenant_id,
-                        ram=default_mem_quota)
+        self._update_quota('ram', 0)
         self.assertRaises((lib_exc.Forbidden, lib_exc.OverLimit),
                           self.create_test_server)
 
@@ -90,16 +81,7 @@
     @test.idempotent_id('7c6be468-0274-449a-81c3-ac1c32ee0161')
     def test_create_server_when_instances_quota_is_full(self):
         # Once instances quota limit is reached, disallow server creation
-        quota_set = (self.adm_client.show_quota_set(self.demo_tenant_id)
-                     ['quota_set'])
-        default_instances_quota = quota_set['instances']
-        instances_quota = 0  # Set quota to zero to disallow server creation
-
-        self.adm_client.update_quota_set(self.demo_tenant_id,
-                                         force=True,
-                                         instances=instances_quota)
-        self.addCleanup(self.adm_client.update_quota_set, self.demo_tenant_id,
-                        instances=default_instances_quota)
+        self._update_quota('instances', 0)
         self.assertRaises((lib_exc.Forbidden, lib_exc.OverLimit),
                           self.create_test_server)
 
@@ -109,22 +91,10 @@
     @test.services('network')
     def test_security_groups_exceed_limit(self):
         # Negative test: Creation Security Groups over limit should FAIL
-
-        quota_set = (self.adm_client.show_quota_set(self.demo_tenant_id)
-                     ['quota_set'])
-        default_sg_quota = quota_set['security_groups']
-
         # Set the quota to number of used security groups
         sg_quota = self.limits_client.show_limits()['limits']['absolute'][
             'totalSecurityGroupsUsed']
-
-        self.adm_client.update_quota_set(self.demo_tenant_id,
-                                         force=True,
-                                         security_groups=sg_quota)
-
-        self.addCleanup(self.adm_client.update_quota_set,
-                        self.demo_tenant_id,
-                        security_groups=default_sg_quota)
+        self._update_quota('security_groups', sg_quota)
 
         # Check we cannot create anymore
         # A 403 Forbidden or 413 Overlimit (old behaviour) exception
@@ -141,19 +111,7 @@
     def test_security_groups_rules_exceed_limit(self):
         # Negative test: Creation of Security Group Rules should FAIL
         # when we reach limit maxSecurityGroupRules
-
-        quota_set = (self.adm_client.show_quota_set(self.demo_tenant_id)
-                     ['quota_set'])
-        default_sg_rules_quota = quota_set['security_group_rules']
-        sg_rules_quota = 0  # Set the quota to zero to conserve resources
-
-        self.adm_client.update_quota_set(self.demo_tenant_id,
-                                         force=True,
-                                         security_group_rules=sg_rules_quota)
-
-        self.addCleanup(self.adm_client.update_quota_set,
-                        self.demo_tenant_id,
-                        security_group_rules=default_sg_rules_quota)
+        self._update_quota('security_group_rules', 0)
 
         s_name = data_utils.rand_name('securitygroup')
         s_description = data_utils.rand_name('description')