diff --git a/stdlib/2and3/_typeshed/__init__.pyi b/stdlib/2and3/_typeshed/__init__.pyi
index 3f64d2e6e..8ace27871 100644
--- a/stdlib/2and3/_typeshed/__init__.pyi
+++ b/stdlib/2and3/_typeshed/__init__.pyi
@@ -12,6 +12,8 @@
 # If on Python versions < 3.10 and "from __future__ import annotations"
 # is not used, types from this module must be quoted.
 
+import array
+import mmap
 import sys
 from typing import Protocol, Text, TypeVar, Union
 from typing_extensions import Literal
@@ -67,3 +69,6 @@ class SupportsReadline(Protocol[_T_co]):
     def readline(self, __length: int = ...) -> _T_co: ...
 class SupportsWrite(Protocol[_T_contra]):
     def write(self, __s: _T_contra) -> int: ...
+
+ReadableBuffer = Union[bytes, bytearray, memoryview, array.array, mmap.mmap]
+WriteableBuffer = Union[bytearray, memoryview, array.array, mmap.mmap]
diff --git a/stdlib/3/gzip.pyi b/stdlib/3/gzip.pyi
index 57d4e212c..f2976dcb2 100644
--- a/stdlib/3/gzip.pyi
+++ b/stdlib/3/gzip.pyi
@@ -2,7 +2,7 @@ import sys
 import zlib
 from typing import IO, Optional, TextIO, Union, overload
 import _compression
-from _typeshed import AnyPath
+from _typeshed import AnyPath, ReadableBuffer
 from typing_extensions import Literal
 
 _OpenBinaryMode = Literal["r", "rb", "a", "ab", "w", "wb", "x", "xb"]
@@ -63,7 +63,7 @@ class GzipFile(_compression.BaseStream):
     @property
     def mtime(self) -> Optional[int]: ...
     crc: int
-    def write(self, data: bytes) -> int: ...
+    def write(self, data: ReadableBuffer) -> int: ...
     def read(self, size: Optional[int] = ...) -> bytes: ...
     def read1(self, size: int = ...) -> bytes: ...
     def peek(self, n: int) -> bytes: ...
diff --git a/stdlib/3/io.pyi b/stdlib/3/io.pyi
index 1ca15c9a3..e1e732c9e 100644
--- a/stdlib/3/io.pyi
+++ b/stdlib/3/io.pyi
@@ -6,8 +6,7 @@ import codecs
 import sys
 from mmap import mmap
 from types import TracebackType
-
-_bytearray_like = Union[bytearray, mmap]
+from _typeshed import ReadableBuffer, WriteableBuffer
 
 DEFAULT_BUFFER_SIZE: int
 
@@ -42,7 +41,7 @@ class IOBase:
     def tell(self) -> int: ...
     def truncate(self, __size: Optional[int] = ...) -> int: ...
     def writable(self) -> bool: ...
-    def writelines(self, __lines: Iterable[Union[bytes, bytearray]]) -> None: ...
+    def writelines(self, __lines: Iterable[ReadableBuffer]) -> None: ...
     def readline(self, __size: Optional[int] = ...) -> bytes: ...
     def __del__(self) -> None: ...
     @property
@@ -51,16 +50,16 @@ class IOBase:
 
 class RawIOBase(IOBase):
     def readall(self) -> bytes: ...
-    def readinto(self, __buffer: bytearray) -> Optional[int]: ...
-    def write(self, __b: Union[bytes, bytearray]) -> Optional[int]: ...
+    def readinto(self, __buffer: WriteableBuffer) -> Optional[int]: ...
+    def write(self, __b: ReadableBuffer) -> Optional[int]: ...
     def read(self, __size: int = ...) -> Optional[bytes]: ...
 
 class BufferedIOBase(IOBase):
     raw: RawIOBase  # This is not part of the BufferedIOBase API and may not exist on some implementations.
     def detach(self) -> RawIOBase: ...
-    def readinto(self, __buffer: _bytearray_like) -> int: ...
-    def write(self, __buffer: Union[bytes, bytearray]) -> int: ...
-    def readinto1(self, __buffer: _bytearray_like) -> int: ...
+    def readinto(self, __buffer: WriteableBuffer) -> int: ...
+    def write(self, __buffer: ReadableBuffer) -> int: ...
+    def readinto1(self, __buffer: WriteableBuffer) -> int: ...
     def read(self, __size: Optional[int] = ...) -> bytes: ...
     def read1(self, __size: int = ...) -> bytes: ...
 
@@ -75,7 +74,7 @@ class FileIO(RawIOBase, BinaryIO):
         closefd: bool = ...,
         opener: Optional[Callable[[Union[int, str], str], int]] = ...
     ) -> None: ...
-    def write(self, __b: bytes) -> int: ...
+    def write(self, __b: ReadableBuffer) -> int: ...
     def read(self, __size: int = ...) -> bytes: ...
     def __enter__(self: _T) -> _T: ...
 
@@ -105,7 +104,7 @@ class BufferedReader(BufferedIOBase, BinaryIO):
 class BufferedWriter(BufferedIOBase, BinaryIO):
     def __enter__(self: _T) -> _T: ...
     def __init__(self, raw: RawIOBase, buffer_size: int = ...) -> None: ...
-    def write(self, __buffer: Union[bytes, bytearray]) -> int: ...
+    def write(self, __buffer: ReadableBuffer) -> int: ...
 
 class BufferedRandom(BufferedReader, BufferedWriter):
     def __enter__(self: _T) -> _T: ...
diff --git a/stdlib/3/lzma.pyi b/stdlib/3/lzma.pyi
index 3a06895ec..30e71e0ec 100644
--- a/stdlib/3/lzma.pyi
+++ b/stdlib/3/lzma.pyi
@@ -1,6 +1,6 @@
 import io
 from typing import IO, Any, Mapping, Optional, Sequence, TextIO, TypeVar, Union, overload
-from _typeshed import AnyPath
+from _typeshed import AnyPath, ReadableBuffer
 from typing_extensions import Literal
 
 _OpenBinaryWritingMode = Literal["w", "wb", "x", "xb", "a", "ab"]
@@ -88,7 +88,7 @@ class LZMAFile(io.BufferedIOBase, IO[bytes]):
     def read(self, size: Optional[int] = ...) -> bytes: ...
     def read1(self, size: int = ...) -> bytes: ...
     def readline(self, size: Optional[int] = ...) -> bytes: ...
-    def write(self, data: bytes) -> int: ...
+    def write(self, data: ReadableBuffer) -> int: ...
     def seek(self, offset: int, whence: int = ...) -> int: ...
     def tell(self) -> int: ...