diff --git a/stdlib/2and3/codecs.pyi b/stdlib/2and3/codecs.pyi
index fe734511b..7c06ee937 100644
--- a/stdlib/2and3/codecs.pyi
+++ b/stdlib/2and3/codecs.pyi
@@ -65,7 +65,7 @@ def getincrementalencoder(encoding: str) -> _IncrementalEncoder: ...
 def getincrementaldecoder(encoding: str) -> _IncrementalDecoder: ...
 def getreader(encoding: str) -> _StreamReader: ...
 def getwriter(encoding: str) -> _StreamWriter: ...
-def register(search_function: Callable[[str], CodecInfo]) -> None: ...
+def register(search_function: Callable[[str], Optional[CodecInfo]]) -> None: ...
 def open(filename: str, mode: str = ..., encoding: str = ..., errors: str = ..., buffering: int = ...) -> StreamReaderWriter: ...
 def EncodedFile(file: IO[_Encoded], data_encoding: str, file_encoding: str = ..., errors: str = ...) -> StreamRecoder: ...
 def iterencode(iterator: Iterable[_Decoded], encoding: str, errors: str = ...) -> Generator[_Encoded, None, None]: ...