diff --git a/stdlib/builtins.pyi b/stdlib/builtins.pyi
index 38be452e8d49..4b3d5ff7a70f 100644
--- a/stdlib/builtins.pyi
+++ b/stdlib/builtins.pyi
@@ -79,7 +79,8 @@ if sys.version_info >= (3, 14):
     from _typeshed import AnnotateFunc
 
 _T = TypeVar("_T")
-_I = TypeVar("_I", default=int)
+# Type ignore needed because of https://github.com/python/mypy/issues/20184.
+_I = TypeVar("_I", int, bytes, float, bool, default=Any)  # type: ignore[misc]  # possibly memoryview types
 _T_co = TypeVar("_T_co", covariant=True)
 _T_contra = TypeVar("_T_contra", contravariant=True)
 _R_co = TypeVar("_R_co", covariant=True)
@@ -919,7 +920,7 @@ class memoryview(Sequence[_I]):
     @overload
     def cast(self, format: Literal["?"], shape: list[int] | tuple[int, ...] = ...) -> memoryview[bool]: ...
     @overload
-    def cast(self, format: _IntegerFormats, shape: list[int] | tuple[int, ...] = ...) -> memoryview: ...
+    def cast(self, format: _IntegerFormats, shape: list[int] | tuple[int, ...] = ...) -> memoryview[int]: ...
     @overload
     def __getitem__(self, key: SupportsIndex | tuple[SupportsIndex, ...], /) -> _I: ...
     @overload