diff --git a/stdlib/_codecs.pyi b/stdlib/_codecs.pyi
index 9241ac6a7038..232256fbf614 100644
--- a/stdlib/_codecs.pyi
+++ b/stdlib/_codecs.pyi
@@ -1,5 +1,6 @@
 import codecs
 import sys
+from _typeshed import ReadableBuffer
 from collections.abc import Callable
 from typing import overload
 from typing_extensions import Literal, TypeAlias
@@ -44,13 +45,13 @@ _BytesToBytesEncoding: TypeAlias = Literal[
 _StrToStrEncoding: TypeAlias = Literal["rot13", "rot_13"]
 
 @overload
-def encode(obj: bytes, encoding: _BytesToBytesEncoding, errors: str = ...) -> bytes: ...
+def encode(obj: ReadableBuffer, encoding: _BytesToBytesEncoding, errors: str = ...) -> bytes: ...
 @overload
 def encode(obj: str, encoding: _StrToStrEncoding, errors: str = ...) -> str: ...  # type: ignore[misc]
 @overload
 def encode(obj: str, encoding: str = ..., errors: str = ...) -> bytes: ...
 @overload
-def decode(obj: bytes, encoding: _BytesToBytesEncoding, errors: str = ...) -> bytes: ...  # type: ignore[misc]
+def decode(obj: ReadableBuffer, encoding: _BytesToBytesEncoding, errors: str = ...) -> bytes: ...  # type: ignore[misc]
 @overload
 def decode(obj: str, encoding: _StrToStrEncoding, errors: str = ...) -> str: ...
 
@@ -64,66 +65,72 @@ def decode(
 @overload
 def decode(obj: str, encoding: Literal["hex", "hex_codec"], errors: str = ...) -> bytes: ...
 @overload
-def decode(obj: bytes, encoding: str = ..., errors: str = ...) -> str: ...
+def decode(obj: ReadableBuffer, encoding: str = ..., errors: str = ...) -> str: ...
 def lookup(__encoding: str) -> codecs.CodecInfo: ...
 def charmap_build(__map: str) -> _CharMap: ...
-def ascii_decode(__data: bytes, __errors: str | None = ...) -> tuple[str, int]: ...
+def ascii_decode(__data: ReadableBuffer, __errors: str | None = ...) -> tuple[str, int]: ...
 def ascii_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
-def charmap_decode(__data: bytes, __errors: str | None = ..., __mapping: _CharMap | None = ...) -> tuple[str, int]: ...
+def charmap_decode(__data: ReadableBuffer, __errors: str | None = ..., __mapping: _CharMap | None = ...) -> tuple[str, int]: ...
 def charmap_encode(__str: str, __errors: str | None = ..., __mapping: _CharMap | None = ...) -> tuple[bytes, int]: ...
-def escape_decode(__data: str | bytes, __errors: str | None = ...) -> tuple[str, int]: ...
+def escape_decode(__data: str | ReadableBuffer, __errors: str | None = ...) -> tuple[str, int]: ...
 def escape_encode(__data: bytes, __errors: str | None = ...) -> tuple[bytes, int]: ...
-def latin_1_decode(__data: bytes, __errors: str | None = ...) -> tuple[str, int]: ...
+def latin_1_decode(__data: ReadableBuffer, __errors: str | None = ...) -> tuple[str, int]: ...
 def latin_1_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
 
 if sys.version_info >= (3, 9):
-    def raw_unicode_escape_decode(__data: str | bytes, __errors: str | None = ..., __final: bool = ...) -> tuple[str, int]: ...
+    def raw_unicode_escape_decode(
+        __data: str | ReadableBuffer, __errors: str | None = ..., __final: bool = ...
+    ) -> tuple[str, int]: ...
 
 else:
-    def raw_unicode_escape_decode(__data: str | bytes, __errors: str | None = ...) -> tuple[str, int]: ...
+    def raw_unicode_escape_decode(__data: str | ReadableBuffer, __errors: str | None = ...) -> tuple[str, int]: ...
 
 def raw_unicode_escape_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
-def readbuffer_encode(__data: str | bytes, __errors: str | None = ...) -> tuple[bytes, int]: ...
+def readbuffer_encode(__data: str | ReadableBuffer, __errors: str | None = ...) -> tuple[bytes, int]: ...
 
 if sys.version_info >= (3, 9):
-    def unicode_escape_decode(__data: str | bytes, __errors: str | None = ..., __final: bool = ...) -> tuple[str, int]: ...
+    def unicode_escape_decode(
+        __data: str | ReadableBuffer, __errors: str | None = ..., __final: bool = ...
+    ) -> tuple[str, int]: ...
 
 else:
-    def unicode_escape_decode(__data: str | bytes, __errors: str | None = ...) -> tuple[str, int]: ...
+    def unicode_escape_decode(__data: str | ReadableBuffer, __errors: str | None = ...) -> tuple[str, int]: ...
 
 def unicode_escape_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
 
 if sys.version_info < (3, 8):
-    def unicode_internal_decode(__obj: str | bytes, __errors: str | None = ...) -> tuple[str, int]: ...
-    def unicode_internal_encode(__obj: str | bytes, __errors: str | None = ...) -> tuple[bytes, int]: ...
+    def unicode_internal_decode(__obj: str | ReadableBuffer, __errors: str | None = ...) -> tuple[str, int]: ...
+    def unicode_internal_encode(__obj: str | ReadableBuffer, __errors: str | None = ...) -> tuple[bytes, int]: ...
 
-def utf_16_be_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+def utf_16_be_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
 def utf_16_be_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
-def utf_16_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+def utf_16_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
 def utf_16_encode(__str: str, __errors: str | None = ..., __byteorder: int = ...) -> tuple[bytes, int]: ...
 def utf_16_ex_decode(
-    __data: bytes, __errors: str | None = ..., __byteorder: int = ..., __final: int = ...
+    __data: ReadableBuffer, __errors: str | None = ..., __byteorder: int = ..., __final: int = ...
 ) -> tuple[str, int, int]: ...
-def utf_16_le_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+def utf_16_le_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
 def utf_16_le_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
-def utf_32_be_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+def utf_32_be_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
 def utf_32_be_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
-def utf_32_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+def utf_32_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
 def utf_32_encode(__str: str, __errors: str | None = ..., __byteorder: int = ...) -> tuple[bytes, int]: ...
 def utf_32_ex_decode(
-    __data: bytes, __errors: str | None = ..., __byteorder: int = ..., __final: int = ...
+    __data: ReadableBuffer, __errors: str | None = ..., __byteorder: int = ..., __final: int = ...
 ) -> tuple[str, int, int]: ...
-def utf_32_le_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+def utf_32_le_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
 def utf_32_le_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
-def utf_7_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+def utf_7_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
 def utf_7_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
-def utf_8_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+def utf_8_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
 def utf_8_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
 
 if sys.platform == "win32":
-    def mbcs_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+    def mbcs_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
     def mbcs_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
-    def code_page_decode(__codepage: int, __data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+    def code_page_decode(
+        __codepage: int, __data: ReadableBuffer, __errors: str | None = ..., __final: int = ...
+    ) -> tuple[str, int]: ...
     def code_page_encode(__code_page: int, __str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...
-    def oem_decode(__data: bytes, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
+    def oem_decode(__data: ReadableBuffer, __errors: str | None = ..., __final: int = ...) -> tuple[str, int]: ...
     def oem_encode(__str: str, __errors: str | None = ...) -> tuple[bytes, int]: ...