diff --git a/pyproject.toml b/pyproject.toml
index e9722711b1..80e03322a6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -177,7 +177,6 @@ extend-select = [
 ignore = [
     "RUF003",
     "RUF005",
-    "RUF009",
     "RUF012",
     "RUF015",
 ]
diff --git a/src/zarr/metadata.py b/src/zarr/metadata.py
index 39a1d53199..b461449991 100644
--- a/src/zarr/metadata.py
+++ b/src/zarr/metadata.py
@@ -5,7 +5,7 @@
 from collections.abc import Iterable
 from dataclasses import dataclass, field, replace
 from enum import Enum
-from typing import TYPE_CHECKING, Any, cast
+from typing import TYPE_CHECKING, Any
 
 import numpy as np
 import numpy.typing as npt
@@ -310,7 +310,7 @@ class ArrayV2Metadata(ArrayMetadata):
     filters: list[dict[str, JSON]] | None = None
     dimension_separator: Literal[".", "/"] = "."
     compressor: dict[str, JSON] | None = None
-    attributes: dict[str, JSON] = cast(dict[str, JSON], field(default_factory=dict))
+    attributes: dict[str, JSON] = field(default_factory=dict)
     zarr_format: Literal[2] = field(init=False, default=2)
 
     def __init__(