diff --git a/pkg/controller/subnet.go b/pkg/controller/subnet.go
index c6b215db3d02..47c9d806faa7 100644
--- a/pkg/controller/subnet.go
+++ b/pkg/controller/subnet.go
@@ -479,8 +479,15 @@ func checkAndUpdateExcludeIPs(subnet *kubeovnv1.Subnet) bool {
 
 func (c *Controller) handleSubnetFinalizer(subnet *kubeovnv1.Subnet) (bool, error) {
 	if subnet.DeletionTimestamp.IsZero() && !util.ContainsString(subnet.Finalizers, util.ControllerName) {
-		subnet.Finalizers = append(subnet.Finalizers, util.ControllerName)
-		if _, err := c.config.KubeOvnClient.KubeovnV1().Subnets().Update(context.Background(), subnet, metav1.UpdateOptions{}); err != nil {
+		newSubnet := subnet.DeepCopy()
+		newSubnet.Finalizers = append(newSubnet.Finalizers, util.ControllerName)
+		patch, err := util.GenerateMergePatchPayload(subnet, newSubnet)
+		if err != nil {
+			klog.Errorf("failed to generate patch payload for subnet '%s', %v", subnet.Name, err)
+			return false, err
+		}
+		if _, err := c.config.KubeOvnClient.KubeovnV1().Subnets().Patch(context.Background(), subnet.Name,
+			types.MergePatchType, patch, metav1.PatchOptions{}, ""); err != nil {
 			klog.Errorf("failed to add finalizer to subnet %s, %v", subnet.Name, err)
 			return false, err
 		}
@@ -496,8 +503,15 @@ func (c *Controller) handleSubnetFinalizer(subnet *kubeovnv1.Subnet) (bool, erro
 
 	u2oInterconnIP := subnet.Status.U2OInterconnectionIP
 	if !subnet.DeletionTimestamp.IsZero() && (usingIPs == 0 || (usingIPs == 1 && u2oInterconnIP != "")) {
-		subnet.Finalizers = util.RemoveString(subnet.Finalizers, util.ControllerName)
-		if _, err := c.config.KubeOvnClient.KubeovnV1().Subnets().Update(context.Background(), subnet, metav1.UpdateOptions{}); err != nil {
+		newSubnet := subnet.DeepCopy()
+		newSubnet.Finalizers = util.RemoveString(newSubnet.Finalizers, util.ControllerName)
+		patch, err := util.GenerateMergePatchPayload(subnet, newSubnet)
+		if err != nil {
+			klog.Errorf("failed to generate patch payload for subnet '%s', %v", subnet.Name, err)
+			return false, err
+		}
+		if _, err := c.config.KubeOvnClient.KubeovnV1().Subnets().Patch(context.Background(), subnet.Name,
+			types.MergePatchType, patch, metav1.PatchOptions{}, ""); err != nil {
 			klog.Errorf("failed to remove finalizer from subnet %s, %v", subnet.Name, err)
 			return false, err
 		}
diff --git a/test/e2e/ovn-vpc-nat-gw/e2e_test.go b/test/e2e/ovn-vpc-nat-gw/e2e_test.go
index c6814089f259..d7baebd09c80 100644
--- a/test/e2e/ovn-vpc-nat-gw/e2e_test.go
+++ b/test/e2e/ovn-vpc-nat-gw/e2e_test.go
@@ -158,7 +158,7 @@ var _ = framework.Describe("[group:ovn-vpc-nat-gw]", func() {
 		providerNetworkName = "external"
 		providerExtraNetworkName = "extra"
 		vlanName = "vlan-" + framework.RandomSuffix()
-		vlanExtraName = "vlan-extra" + framework.RandomSuffix()
+		vlanExtraName = "vlan-extra-" + framework.RandomSuffix()
 		underlaySubnetName = "external"
 		underlayExtraSubnetName = "extra"