diff --git a/stdlib/bz2.pyi b/stdlib/bz2.pyi
index cea317e28..295271d4a 100644
--- a/stdlib/bz2.pyi
+++ b/stdlib/bz2.pyi
@@ -19,8 +19,8 @@ class _WritableFileobj(Protocol):
     # def fileno(self) -> int: ...
     # def close(self) -> object: ...
 
-def compress(data: bytes, compresslevel: int = ...) -> bytes: ...
-def decompress(data: bytes) -> bytes: ...
+def compress(data: ReadableBuffer, compresslevel: int = ...) -> bytes: ...
+def decompress(data: ReadableBuffer) -> bytes: ...
 
 _ReadBinaryMode: TypeAlias = Literal["", "r", "rb"]
 _WriteBinaryMode: TypeAlias = Literal["w", "wb", "x", "xb", "a", "ab"]
@@ -132,12 +132,12 @@ class BZ2File(BaseStream, IO[bytes]):
 @final
 class BZ2Compressor:
     def __init__(self, compresslevel: int = ...) -> None: ...
-    def compress(self, __data: bytes) -> bytes: ...
+    def compress(self, __data: ReadableBuffer) -> bytes: ...
     def flush(self) -> bytes: ...
 
 @final
 class BZ2Decompressor:
-    def decompress(self, data: bytes, max_length: int = ...) -> bytes: ...
+    def decompress(self, data: ReadableBuffer, max_length: int = ...) -> bytes: ...
     @property
     def eof(self) -> bool: ...
     @property