diff --git a/xarray/namedarray/_typing.py b/xarray/namedarray/_typing.py
index 99a20ac891a..95260f30c20 100644
--- a/xarray/namedarray/_typing.py
+++ b/xarray/namedarray/_typing.py
@@ -84,7 +84,7 @@ def dtype(self) -> _DType_co: ...
 _ChunksType = TypeVar("_ChunksType", bound=_Chunks)
 
 # FYI in some cases we don't allow `None`, which this doesn't take account of.
-T_ChunkDim: TypeAlias = Union[int, Literal["auto"], None, tuple[int, ...]]
+T_ChunkDim: TypeAlias = Union[int, Literal["auto"], None, _Chunk]
 # We allow the tuple form of this (though arguably we could transition to named dims only)
 T_Chunks: TypeAlias = Union[T_ChunkDim, Mapping[Any, T_ChunkDim]]