diff --git a/tempest/api/compute/servers/test_attach_interfaces.py b/tempest/api/compute/servers/test_attach_interfaces.py
index 530e422..24d503f 100644
--- a/tempest/api/compute/servers/test_attach_interfaces.py
+++ b/tempest/api/compute/servers/test_attach_interfaces.py
@@ -186,7 +186,7 @@
         self.assertTrue(interface_count > 0)
         self._check_interface(ifs[0])
         network_id = ifs[0]['net_id']
-        self.client.add_fixed_ip(server['id'], networkId=network_id)
+        self.servers_client.add_fixed_ip(server['id'], networkId=network_id)
         # Remove the fixed IP from server.
         server_detail = self.os.servers_client.show_server(
             server['id'])['server']
@@ -199,4 +199,4 @@
                     break
             if fixed_ip is not None:
                 break
-        self.client.remove_fixed_ip(server['id'], address=fixed_ip)
+        self.servers_client.remove_fixed_ip(server['id'], address=fixed_ip)
diff --git a/tempest/services/compute/json/interfaces_client.py b/tempest/services/compute/json/interfaces_client.py
index 2e66082..fe076d8 100644
--- a/tempest/services/compute/json/interfaces_client.py
+++ b/tempest/services/compute/json/interfaces_client.py
@@ -16,7 +16,6 @@
 from oslo_serialization import jsonutils as json
 
 from tempest.api_schema.response.compute.v2_1 import interfaces as schema
-from tempest.api_schema.response.compute.v2_1 import servers as servers_schema
 from tempest.common import service_client
 
 
@@ -49,21 +48,3 @@
                                                                  port_id))
         self.validate_response(schema.delete_interface, resp, body)
         return service_client.ResponseBody(resp, body)
-
-    def add_fixed_ip(self, server_id, **kwargs):
-        """Add a fixed IP to input server instance."""
-        post_body = json.dumps({'addFixedIp': kwargs})
-        resp, body = self.post('servers/%s/action' % server_id,
-                               post_body)
-        self.validate_response(servers_schema.server_actions_common_schema,
-                               resp, body)
-        return service_client.ResponseBody(resp, body)
-
-    def remove_fixed_ip(self, server_id, **kwargs):
-        """Remove input fixed IP from input server instance."""
-        post_body = json.dumps({'removeFixedIp': kwargs})
-        resp, body = self.post('servers/%s/action' % server_id,
-                               post_body)
-        self.validate_response(servers_schema.server_actions_common_schema,
-                               resp, body)
-        return service_client.ResponseBody(resp, body)
diff --git a/tempest/services/compute/json/servers_client.py b/tempest/services/compute/json/servers_client.py
index a36603f..e07bfeb 100644
--- a/tempest/services/compute/json/servers_client.py
+++ b/tempest/services/compute/json/servers_client.py
@@ -457,3 +457,11 @@
         return self.action(server_id, "os-getVNCConsole",
                            schema.get_vnc_console,
                            type=console_type)
+
+    def add_fixed_ip(self, server_id, **kwargs):
+        """Add a fixed IP to input server instance."""
+        return self.action(server_id, 'addFixedIp', **kwargs)
+
+    def remove_fixed_ip(self, server_id, **kwargs):
+        """Remove input fixed IP from input server instance."""
+        return self.action(server_id, 'removeFixedIp', **kwargs)