diff --git a/neutron_tempest_plugin/scenario/test_dhcp.py b/neutron_tempest_plugin/scenario/test_dhcp.py
index 31d2930..defe37b 100644
--- a/neutron_tempest_plugin/scenario/test_dhcp.py
+++ b/neutron_tempest_plugin/scenario/test_dhcp.py
@@ -11,7 +11,6 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
-import netaddr
 from neutron_lib import constants
 from oslo_log import log
 from paramiko import ssh_exception as ssh_exc
@@ -160,12 +159,10 @@
         dhcp_port = self.dhcp_ports[0]
 
         # modify DHCP port IP address
-        old_dhcp_port_ip = netaddr.IPAddress(
-            dhcp_port['fixed_ips'][0]['ip_address'])
-        if str(old_dhcp_port_ip) != subnet['allocation_pools'][0]['end']:
-            new_dhcp_port_ip = str(old_dhcp_port_ip + 1)
-        else:
-            new_dhcp_port_ip = str(old_dhcp_port_ip - 1)
+        new_dhcp_port_ip = utils.net_utils.get_unused_ip_addresses(
+            ports_client=self.client, subnets_client=self.client,
+            network_id=self.network['id'], subnet_id=subnet['id'],
+            count=1)[0]
         self.update_port(port=dhcp_port,
                          fixed_ips=[{'subnet_id': subnet['id'],
                                      'ip_address': new_dhcp_port_ip}])