diff --git a/custom_components/diveracontrol/__init__.py b/custom_components/diveracontrol/__init__.py
index e98e0b9..7cc5dad 100644
--- a/custom_components/diveracontrol/__init__.py
+++ b/custom_components/diveracontrol/__init__.py
@@ -43,7 +43,10 @@
 from .coordinator import DiveraCoordinator
 from .divera_api import DiveraAPIClient
 from .service import async_register_services
-from .utils import get_cluster_coordinators_ucrs_from_config_hass
+from .utils import (
+    get_cluster_coordinators_ucrs_from_config_hass,
+    get_device_config_entry_ids,
+)
 
 PLATFORMS: list[Platform] = [
     Platform.CALENDAR,
@@ -504,7 +507,7 @@ def _remove_old_entity_entries(
                 and identifier[1] in config_entry.data.get(D_RELATIONS_KEY, {})
                 for identifier in d.identifiers
             )
-            or not d.config_entry_id  # Orphaned devices
+            or not get_device_config_entry_ids(d)  # Orphaned devices
         ]
 
         # 3. Zusammenführen und Duplikate vermeiden
@@ -521,7 +524,7 @@ def _remove_old_entity_entries(
                 "Migration: removing old device %s (name=%s, config_entry_id=%s)",
                 device.id,
                 device.name_by_user or device.name,
-                device.config_entry_id,
+                get_device_config_entry_ids(device) or None,
             )
             dev_reg.async_remove_device(device.id)
 
diff --git a/custom_components/diveracontrol/device_action.py b/custom_components/diveracontrol/device_action.py
index c97d9e1..d937f6a 100644
--- a/custom_components/diveracontrol/device_action.py
+++ b/custom_components/diveracontrol/device_action.py
@@ -29,7 +29,11 @@
     PERM_STATUS_USER,
     PERM_STATUS_VEHICLE,
 )
-from .utils import get_translation, get_ucr_data_from_device
+from .utils import (
+    get_device_config_entry_ids,
+    get_translation,
+    get_ucr_data_from_device,
+)
 
 ACTION_TYPES: tuple[str, ...] = (
     "request_refresh",
@@ -187,7 +191,7 @@ async def async_get_actions(
     device_registry = dr.async_get(hass)
     device = device_registry.async_get(device_id)
 
-    if not device or not device.config_entry_id:
+    if not device or not get_device_config_entry_ids(device):
         return []
 
     try:
diff --git a/custom_components/diveracontrol/utils.py b/custom_components/diveracontrol/utils.py
index 1eeee11..5dfcefd 100644
--- a/custom_components/diveracontrol/utils.py
+++ b/custom_components/diveracontrol/utils.py
@@ -14,6 +14,31 @@
 _LOGGER = logging.getLogger(__name__)
 
 
+def get_device_config_entry_ids(device: Any) -> tuple[str, ...]:
+    """Return all config entry ids linked to a device.
+
+    Home Assistant 2025.12 replaced ``DeviceEntry.config_entry_id`` with
+    ``primary_config_entry`` and a ``config_entries`` list. This helper works
+    with both the old and the new API.
+
+    Args:
+        device: Device registry entry.
+
+    Returns:
+        Tuple of config entry ids linked to the device.
+    """
+    entry_id = getattr(device, "config_entry_id", None)
+    if entry_id:
+        return (entry_id,)
+    primary = getattr(device, "primary_config_entry", None)
+    if primary:
+        return (
+            primary,
+            *(e for e in getattr(device, "config_entries", ()) if e and e != primary),
+        )
+    return ()
+
+
 def get_ucr_data_from_device(
     hass: HomeAssistant,
     device_id: str,
@@ -36,18 +61,20 @@ def get_ucr_data_from_device(
     device_registry = dr.async_get(hass)
     device = device_registry.async_get(device_id)
 
-    if not device or not device.config_entry_id:
+    if not device or not get_device_config_entry_ids(device):
         raise HomeAssistantError(
             f"Device not found or has no config entries: {device_id}"
         )
 
-    # Get config entry
-    config_entry_id = device.config_entry_id
-    if not config_entry_id:
-        raise HomeAssistantError(f"Config entry not found for device: {device_id}")
+    # Get config entry (prefer an entry belonging to this integration)
+    entry = None
+    for config_entry_id in get_device_config_entry_ids(device):
+        candidate = hass.config_entries.async_get_entry(config_entry_id)
+        if candidate and candidate.domain == DOMAIN:
+            entry = candidate
+            break
 
-    entry = hass.config_entries.async_get_entry(config_entry_id)
-    if not entry or entry.domain != DOMAIN:
+    if entry is None:
         raise HomeAssistantError(f"Invalid config entry for device: {device_id}")
 
     # Get cluster_id