diff --git a/stdlib/@tests/test_cases/typing/check_MutableMapping.py b/stdlib/@tests/test_cases/typing/check_MutableMapping.py
index d4f951060b35..b4916351703f 100644
--- a/stdlib/@tests/test_cases/typing/check_MutableMapping.py
+++ b/stdlib/@tests/test_cases/typing/check_MutableMapping.py
@@ -30,6 +30,14 @@ def check_update_method__str_key() -> None:
     d.update([("", "")])  # type: ignore
 
 
+def check_update_kwarg_key_type_accepts_str() -> None:
+    d1: dict[str | int, int] = {}
+    d1.update(a=1)
+
+    d2: dict[object, int] = {}
+    d2.update(a=1)
+
+
 def check_setdefault_method() -> None:
     d: dict[int, str] = {}
     d2: dict[int, str | None] = {}
diff --git a/stdlib/typing.pyi b/stdlib/typing.pyi
index d296c8d92149..d45d6b5076fc 100644
--- a/stdlib/typing.pyi
+++ b/stdlib/typing.pyi
@@ -800,13 +800,13 @@ class MutableMapping(Mapping[_KT, _VT]):
     @overload
     def update(self, m: SupportsKeysAndGetItem[_KT, _VT], /) -> None: ...
     @overload
-    def update(self: Mapping[str, _VT], m: SupportsKeysAndGetItem[str, _VT], /, **kwargs: _VT) -> None: ...
+    def update(self: Mapping[str | Any, _VT], m: SupportsKeysAndGetItem[str, _VT], /, **kwargs: _VT) -> None: ...
     @overload
     def update(self, m: Iterable[tuple[_KT, _VT]], /) -> None: ...
     @overload
-    def update(self: Mapping[str, _VT], m: Iterable[tuple[str, _VT]], /, **kwargs: _VT) -> None: ...
+    def update(self: Mapping[str | Any, _VT], m: Iterable[tuple[str, _VT]], /, **kwargs: _VT) -> None: ...
     @overload
-    def update(self: Mapping[str, _VT], **kwargs: _VT) -> None: ...
+    def update(self: Mapping[str | Any, _VT], **kwargs: _VT) -> None: ...
 
 Text = str