diff --git a/aiohomekit/controller/ble/pairing.py b/aiohomekit/controller/ble/pairing.py
index 4bfaefb3..730d2848 100644
--- a/aiohomekit/controller/ble/pairing.py
+++ b/aiohomekit/controller/ble/pairing.py
@@ -830,8 +830,7 @@ async def _read_signature(
 
     async def _async_fetch_gatt_database(self) -> Accessories:
         logger.debug("%s: Fetching GATT database; rssi=%s", self.name, self.rssi)
-        accessory = Accessory()
-        accessory.aid = 1
+        accessory = Accessory(1)
         # Never use the cache when fetching the GATT database
         services_to_link: list[tuple[Service, list[int]]] = []
         services = self.client.services
diff --git a/aiohomekit/model/__init__.py b/aiohomekit/model/__init__.py
index 880526c0..bfce8b0a 100644
--- a/aiohomekit/model/__init__.py
+++ b/aiohomekit/model/__init__.py
@@ -34,7 +34,6 @@
     CharacteristicsTypes,
 )
 from .feature_flags import FeatureFlags
-from .mixin import get_id
 from .services import Service, ServicesTypes
 
 __all__ = [
@@ -178,9 +177,9 @@ def iid(self, iid: int) -> Characteristic | None:
 class Accessory:
     """Represents a HomeKit accessory."""
 
-    def __init__(self) -> None:
+    def __init__(self, aid: int) -> None:
         """Initialize a new accessory."""
-        self.aid = get_id()
+        self.aid = aid
         self._next_id = 0
         self.services = Services()
         self.characteristics = Characteristics(self.services)
@@ -189,6 +188,7 @@ def __init__(self) -> None:
     @classmethod
     def create_with_info(
         cls,
+        aid: int,
         name: str,
         manufacturer: str,
         model: str,
@@ -200,7 +200,7 @@ def create_with_info(
         This method should only be used for testing purposes as it assigns
         the next available ids to the accessory and services.
         """
-        self = cls()
+        self = cls(aid)
 
         accessory_info = self.add_service(ServicesTypes.ACCESSORY_INFORMATION)
         accessory_info.add_char(CharacteristicsTypes.IDENTIFY, description="Identify")
@@ -278,8 +278,7 @@ def needs_polling(self) -> bool:
     @classmethod
     def create_from_dict(cls, data: dict[str, Any]) -> Accessory:
         """Create an accessory from a dict."""
-        accessory = cls()
-        accessory.aid = data["aid"]
+        accessory = cls(data["aid"])
 
         for service_data in data["services"]:
             service = accessory.add_service(
diff --git a/aiohomekit/model/mixin.py b/aiohomekit/model/mixin.py
deleted file mode 100644
index 8997fbbe..00000000
--- a/aiohomekit/model/mixin.py
+++ /dev/null
@@ -1,23 +0,0 @@
-#
-# Copyright 2019 aiohomekit team
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#    http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
-id_counter = 0
-
-
-def get_id() -> int:
-    global id_counter
-    id_counter += 1
-    return id_counter
diff --git a/tests/conftest.py b/tests/conftest.py
index a584e1bf..99c21e79 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -13,7 +13,7 @@
 
 from aiohomekit import Controller
 from aiohomekit.controller.ip import IpPairing
-from aiohomekit.model import Accessory, mixin as model_mixin
+from aiohomekit.model import Accessory
 from aiohomekit.model.characteristics import CharacteristicsTypes
 from aiohomekit.model.services import ServicesTypes
 
@@ -82,7 +82,9 @@ def mock_asynczeroconf():
 
 
 @pytest.fixture
-async def controller_and_unpaired_accessory(request, mock_asynczeroconf, event_loop):
+async def controller_and_unpaired_accessory(
+    request, mock_asynczeroconf, event_loop, id_factory
+):
     available_port = next_available_port()
 
     config_file = tempfile.NamedTemporaryFile(delete=False)
@@ -104,12 +106,9 @@ async def controller_and_unpaired_accessory(request, mock_asynczeroconf, event_l
     )
     config_file.close()
 
-    # Make sure get_id() numbers are stable between tests
-    model_mixin.id_counter = 0
-
     httpd = AccessoryServer(config_file.name, None)
     accessory = Accessory.create_with_info(
-        "Testlicht", "lusiardi.de", "Demoserver", "0001", "0.1"
+        id_factory(), "Testlicht", "lusiardi.de", "Demoserver", "0001", "0.1"
     )
     lightBulbService = accessory.add_service(ServicesTypes.LIGHTBULB)
     lightBulbService.add_char(CharacteristicsTypes.ON, value=False)
@@ -138,7 +137,9 @@ def _shutdown():
 
 
 @pytest.fixture
-async def controller_and_paired_accessory(request, event_loop, mock_asynczeroconf):
+async def controller_and_paired_accessory(
+    request, event_loop, mock_asynczeroconf, id_factory
+):
     available_port = next_available_port()
 
     config_file = tempfile.NamedTemporaryFile(delete=False)
@@ -166,12 +167,9 @@ async def controller_and_paired_accessory(request, event_loop, mock_asynczerocon
     config_file.write(data)
     config_file.close()
 
-    # Make sure get_id() numbers are stable between tests
-    model_mixin.id_counter = 0
-
     httpd = AccessoryServer(config_file.name, None)
     accessory = Accessory.create_with_info(
-        "Testlicht", "lusiardi.de", "Demoserver", "0001", "0.1"
+        id_factory(), "Testlicht", "lusiardi.de", "Demoserver", "0001", "0.1"
     )
     lightBulbService = accessory.add_service(ServicesTypes.LIGHTBULB)
     lightBulbService.add_char(CharacteristicsTypes.ON, value=False)
@@ -253,3 +251,15 @@ async def pairings(request, controller_and_paired_accessory, event_loop):
 @pytest.fixture(autouse=True)
 def configure_test_logging(caplog):
     caplog.set_level(logging.DEBUG)
+
+
+@pytest.fixture()
+def id_factory():
+    id_counter = 0
+
+    def _get_id():
+        nonlocal id_counter
+        id_counter += 1
+        return id_counter
+
+    yield _get_id
diff --git a/tests/test_testing.py b/tests/test_testing.py
index e8b9c008..f993f6de 100644
--- a/tests/test_testing.py
+++ b/tests/test_testing.py
@@ -89,9 +89,10 @@ async def test_update_named_service_events():
     assert accessories.aid(1).characteristics.iid(8).value == 1
 
 
-async def test_update_named_service_events_manual_accessory():
+async def test_update_named_service_events_manual_accessory(id_factory):
     accessories = Accessories()
     accessory = Accessory.create_with_info(
+        id_factory(),
         name="TestLight",
         manufacturer="Test Mfr",
         model="Test Bulb",
@@ -117,9 +118,10 @@ async def test_update_named_service_events_manual_accessory():
     ]
 
 
-async def test_update_named_service_events_manual_accessory_auto_requires():
+async def test_update_named_service_events_manual_accessory_auto_requires(id_factory):
     accessories = Accessories()
     accessory = Accessory.create_with_info(
+        id_factory(),
         name="TestLight",
         manufacturer="Test Mfr",
         model="Test Bulb",
diff --git a/tests/test_utils.py b/tests/test_utils.py
index d7b0bb42..7262b0c4 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -72,8 +72,8 @@ def test_shorten_invalid_uuid():
         shorten_uuid("NOT_A_VALID_UUID")
 
 
-def test_clamp_enum_valid_vals():
-    a = Accessory()
+def test_clamp_enum_valid_vals(id_factory):
+    a = Accessory(id_factory())
     tv_service = a.add_service(service_type=ServicesTypes.TELEVISION)
     char = tv_service.add_char(
         CharacteristicsTypes.REMOTE_KEY,
@@ -86,8 +86,8 @@ def test_clamp_enum_valid_vals():
     assert valid_vals == {RemoteKeyValues.PLAY_PAUSE}
 
 
-def test_clamp_enum_min_max():
-    a = Accessory()
+def test_clamp_enum_min_max(id_factory):
+    a = Accessory(id_factory())
     tv_service = a.add_service(service_type=ServicesTypes.TELEVISION)
     char = tv_service.add_char(
         CharacteristicsTypes.REMOTE_KEY,
@@ -101,8 +101,8 @@ def test_clamp_enum_min_max():
     assert valid_vals == {RemoteKeyValues.PLAY_PAUSE}
 
 
-def test_clamp_enum_min_max_single_press():
-    a = Accessory()
+def test_clamp_enum_min_max_single_press(id_factory):
+    a = Accessory(id_factory())
     tv_service = a.add_service(service_type=ServicesTypes.STATELESS_PROGRAMMABLE_SWITCH)
     char = tv_service.add_char(
         CharacteristicsTypes.INPUT_EVENT,
@@ -116,8 +116,8 @@ def test_clamp_enum_min_max_single_press():
     assert valid_vals == {InputEventValues.SINGLE_PRESS}
 
 
-def test_clamp_enum_min_max_unclamped_button_press():
-    a = Accessory()
+def test_clamp_enum_min_max_unclamped_button_press(id_factory):
+    a = Accessory(id_factory())
     tv_service = a.add_service(service_type=ServicesTypes.STATELESS_PROGRAMMABLE_SWITCH)
     char = tv_service.add_char(
         CharacteristicsTypes.INPUT_EVENT,