diff --git a/stdlib/base64.pyi b/stdlib/base64.pyi
index 67bc37309a97..dd4782142852 100644
--- a/stdlib/base64.pyi
+++ b/stdlib/base64.pyi
@@ -1,6 +1,5 @@
 import sys
-from _typeshed import ReadableBuffer
-from typing import IO
+from _typeshed import ReadableBuffer, SupportsNoArgReadline, SupportsRead, SupportsWrite
 
 __all__ = [
     "encode",
@@ -111,8 +110,8 @@ else:
     def b85encode(b: ReadableBuffer, pad: bool = False) -> bytes: ...
     def b85decode(b: str | ReadableBuffer) -> bytes: ...
 
-def decode(input: IO[bytes], output: IO[bytes]) -> None: ...
-def encode(input: IO[bytes], output: IO[bytes]) -> None: ...
+def decode(input: SupportsNoArgReadline[bytes], output: SupportsWrite[bytes]) -> None: ...
+def encode(input: SupportsRead[bytes], output: SupportsWrite[bytes]) -> None: ...
 def encodebytes(s: ReadableBuffer) -> bytes: ...
 def decodebytes(s: ReadableBuffer) -> bytes: ...