diff --git a/gso/services/netbox_client.py b/gso/services/netbox_client.py
index 5531ab8dc018103f2b2d0f589a15de397cdf0172..9a9d65e042ed7b2823a2a7bc17f1ee3f8ca36483 100644
--- a/gso/services/netbox_client.py
+++ b/gso/services/netbox_client.py
@@ -3,6 +3,7 @@ from uuid import UUID
 
 import pydantic
 import pynetbox
+from pydantic_forms.types import UUIDstr
 from pynetbox.models.dcim import Devices, DeviceTypes, Interfaces
 
 from gso.products.product_types.router import Router
@@ -180,7 +181,6 @@ class NetboxClient:
     def delete_device(self, device_name: str) -> None:
         """Delete device by name."""
         self.netbox.dcim.devices.get(name=device_name).delete()
-        return
 
     def attach_interface_to_lag(
         self, device_name: str, lag_name: str, iface_name: str, description: str | None = None
@@ -288,7 +288,7 @@ class NetboxClient:
         # Convert to bits per second
         return numeric_part * 1000000
 
-    def get_available_interfaces(self, router_id: UUID, speed: str) -> Interfaces:
+    def get_available_interfaces(self, router_id: UUID | UUIDstr, speed: str) -> Interfaces:
         """Return all available interfaces of a device filtered by speed."""
 
         router = Router.from_subscription(router_id).router.router_fqdn
diff --git a/gso/utils/helpers.py b/gso/utils/helpers.py
index 5e3b149ac45f61168c89a925a3fb0426c48fdf1b..b0f493f13662a912d5414fe65860072ec711ce03 100644
--- a/gso/utils/helpers.py
+++ b/gso/utils/helpers.py
@@ -56,7 +56,7 @@ def available_interfaces_choices(router_id: UUID, speed: str) -> Choice | None:
 
 
 def available_interfaces_choices_including_current_members(
-    router_id: UUID, speed: str, interfaces: list[IptrunkInterfaceBlock]
+    router_id: UUID | UUIDstr, speed: str, interfaces: list[IptrunkInterfaceBlock]
 ) -> Choice | None:
     """Return a list of available interfaces for a given router and speed including the current members.
 
@@ -65,6 +65,7 @@ def available_interfaces_choices_including_current_members(
     """
     if Router.from_subscription(router_id).router.router_vendor != RouterVendor.NOKIA:
         return None
+
     available_interfaces = list(NetboxClient().get_available_interfaces(router_id, speed))
     available_interfaces.extend(
         [
diff --git a/test/utils/__init__.py b/test/utils/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/test/utils/test_helpers.py b/test/utils/test_helpers.py
new file mode 100644
index 0000000000000000000000000000000000000000..f8375a4827b4208d09feff1b82fcc523bab85b3b
--- /dev/null
+++ b/test/utils/test_helpers.py
@@ -0,0 +1,64 @@
+from unittest.mock import patch
+
+import pytest
+
+from gso.products.product_blocks.iptrunk import IptrunkInterfaceBlock
+from gso.products.product_blocks.router import RouterVendor
+from gso.utils.helpers import available_interfaces_choices_including_current_members
+
+
+@pytest.fixture
+def mock_router():
+    """Fixture to mock the Router class."""
+    with patch("gso.utils.helpers.Router") as mock:
+        yield mock
+
+
+@pytest.fixture
+def mock_netbox_client():
+    """Fixture to mock the NetboxClient class."""
+    with patch("gso.utils.helpers.NetboxClient") as mock:
+        yield mock
+
+
+def test_non_nokia_router_returns_none(mock_router, faker):
+    mock_router.from_subscription.return_value.router.router_vendor = RouterVendor.JUNIPER
+    result = available_interfaces_choices_including_current_members(faker.uuid4(), "10G", [])
+    assert result is None
+
+
+def test_nokia_router_with_no_interfaces_returns_empty_choice(mock_router, mock_netbox_client, faker):
+    mock_router.from_subscription.return_value.router.router_vendor = RouterVendor.NOKIA
+    mock_netbox_client().get_available_interfaces.return_value = iter([])
+    result = available_interfaces_choices_including_current_members(faker.uuid4(), "10G", [])
+    assert len(result) == 0
+
+
+def test_nokia_router_with_interfaces_returns_choice(mock_router, mock_netbox_client, faker):
+    mock_router.from_subscription.return_value.router.router_vendor = RouterVendor.NOKIA
+    mock_netbox_client().get_available_interfaces.return_value = iter(
+        [
+            {"name": "interface1", "module": {"display": "module1"}, "description": "desc1"},
+            {"name": "interface2", "module": {"display": "module2"}, "description": "desc2"},
+        ]
+    )
+    mock_netbox_client().get_interface_by_name_and_device.return_value = {
+        "name": "interface3",
+        "module": {"display": "module3"},
+        "description": "desc3",
+    }
+    interfaces = [
+        IptrunkInterfaceBlock(
+            interface_name="interface3",
+            interface_description="desc3",
+            owner_subscription_id=faker.uuid4(),
+            subscription_instance_id=faker.uuid4(),
+        )
+    ]
+
+    result = available_interfaces_choices_including_current_members(faker.uuid4(), "10G", interfaces)
+
+    assert len(result) == 3
+    assert hasattr(result, "interface1")
+    assert hasattr(result, "interface2")
+    assert hasattr(result, "interface3")