diff --git a/src/anndata/_types.py b/src/anndata/_types.py
index 9863b43ef..9594a2ab8 100644
--- a/src/anndata/_types.py
+++ b/src/anndata/_types.py
@@ -4,6 +4,7 @@
 
 from __future__ import annotations
 
+from collections.abc import MutableMapping
 from typing import TYPE_CHECKING, Protocol, TypeVar, Union
 
 import numpy as np
@@ -58,7 +59,8 @@
     str,
 ]
 RWAble: TypeAlias = Union[InMemoryArrayOrScalarType, "RWAbleDict", "RWAbleList"]  # noqa: TCH010
-RWAbleDict: TypeAlias = dict[str, RWAble]
+# dict has a broken docstring: https://readthedocs.com/projects/icb-anndata/builds/2342910/
+RWAbleDict: TypeAlias = MutableMapping[str, RWAble]
 RWAbleList: TypeAlias = list[RWAble]
 InMemoryElem: TypeAlias = Union[
     RWAble,