diff --git a/src/hooked_containers/common.py b/src/hooked_containers/common.py
index a7d8d5f..4e79c1f 100644
--- a/src/hooked_containers/common.py
+++ b/src/hooked_containers/common.py
@@ -1,10 +1,12 @@
-from collections.abc import Callable, MutableSequence
+from collections.abc import Callable, MutableMapping, MutableSequence
 from typing import Generic, TypeVar
 
 from . import events as e
 
 T = TypeVar("T")
 
+type MutableNesting[T] = T | MutableSequence[T] | MutableMapping[T, MutableNesting[T]]
+
 
 class HookedContainer(Generic[T]):
     _path: MutableSequence[int]
diff --git a/src/hooked_containers/mapping.py b/src/hooked_containers/mapping.py
index ebd3507..c1162c8 100644
--- a/src/hooked_containers/mapping.py
+++ b/src/hooked_containers/mapping.py
@@ -2,26 +2,26 @@ from collections.abc import MutableMapping, MutableSequence, Sequence
 from copy import copy
 from typing import TypeVar
 
-from .common import HookedContainer
+from .common import HookedContainer, MutableNesting
 from .sequence import HookedList
 
 T = TypeVar("T")
 
 
-class HookedMapping(HookedContainer[T], MutableMapping[T, T | MutableSequence[T] | MutableMapping]):
-    _data: MutableMapping[T, T | MutableSequence[T] | MutableMapping]
+class HookedMapping(HookedContainer[T], MutableMapping[T, MutableNesting[T]]):
+    _data: MutableMapping[T, MutableNesting[T]]
 
     def __init__(
         self,
         hook,
-        existing: MutableMapping[T, T | MutableSequence[T] | MutableMapping],
+        existing: MutableMapping[T, MutableNesting[T]],
         path: Sequence[int] | None = None,
     ):
         self.hook = hook
         self._data = existing
         self._path = list(path) if path is not None else []
 
-    def __getitem__(self, key: T) -> T | MutableSequence[T] | MutableMapping:
+    def __getitem__(self, key: T) -> MutableNesting[T]:
         value = self._data[key]
         match value:
             case MutableMapping() as mapping:
@@ -35,7 +35,7 @@ class HookedMapping(HookedContainer[T], MutableMapping[T, T | MutableSequence[T]
             case _ as item:
                 return item
 
-    def __setitem__(self, key: T, value: T | MutableSequence[T] | MutableMapping) -> None:
+    def __setitem__(self, key: T, value: MutableNesting[T]) -> None:
         self._data[key] = value
         if self.hook:
             from . import events as e