diff --git a/homeassistant/helpers/device_registry.py b/homeassistant/helpers/device_registry.py
index 9c2492d65e8..64d102d020f 100644
--- a/homeassistant/helpers/device_registry.py
+++ b/homeassistant/helpers/device_registry.py
@@ -392,14 +392,14 @@ class DeviceRegistryItems(UserDict[str, _EntryTypeT]):
 
     def __setitem__(self, key: str, entry: _EntryTypeT) -> None:
         """Add an item."""
-        if key in self:
-            old_entry = self[key]
+        data = self.data
+        if key in data:
+            old_entry = data[key]
             for connection in old_entry.connections:
                 del self._connections[connection]
             for identifier in old_entry.identifiers:
                 del self._identifiers[identifier]
-        # type ignore linked to mypy issue: https://github.com/python/mypy/issues/13596
-        super().__setitem__(key, entry)  # type: ignore[assignment]
+        data[key] = entry
         for connection in entry.connections:
             self._connections[connection] = entry
         for identifier in entry.identifiers:
diff --git a/homeassistant/helpers/entity_registry.py b/homeassistant/helpers/entity_registry.py
index 939c8986e71..09f92a88882 100644
--- a/homeassistant/helpers/entity_registry.py
+++ b/homeassistant/helpers/entity_registry.py
@@ -450,11 +450,12 @@ class EntityRegistryItems(UserDict[str, RegistryEntry]):
 
     def __setitem__(self, key: str, entry: RegistryEntry) -> None:
         """Add an item."""
-        if key in self:
-            old_entry = self[key]
+        data = self.data
+        if key in data:
+            old_entry = data[key]
             del self._entry_ids[old_entry.id]
             del self._index[(old_entry.domain, old_entry.platform, old_entry.unique_id)]
-        super().__setitem__(key, entry)
+        data[key] = entry
         self._entry_ids[entry.id] = entry
         self._index[(entry.domain, entry.platform, entry.unique_id)] = entry.entity_id