diff --git a/stdlib/2/_io.pyi b/stdlib/2/_io.pyi
index e85da3317..6e144bcf6 100644
--- a/stdlib/2/_io.pyi
+++ b/stdlib/2/_io.pyi
@@ -1,4 +1,4 @@
-from typing import Any, Optional, Iterable, Tuple, List, Union
+from typing import Any, BinaryIO, Optional, Iterable, Tuple, List, Union
 
 DEFAULT_BUFFER_SIZE = ...  # type: int
 
@@ -9,29 +9,11 @@ class BlockingIOError(IOError):
 class UnsupportedOperation(ValueError, IOError): ...
 
 
-class _IOBase(object):
-    closed = ...  # type: bool
-    def __enter__(self) -> "_IOBase": ...
-    def __exit__(self, type, value, traceback) -> bool: ...
-    def __iter__(self) -> "_IOBase": ...
+class _IOBase(BinaryIO):
     def _checkClosed(self) -> None: ...
     def _checkReadable(self) -> None: ...
     def _checkSeekable(self) -> None: ...
     def _checkWritable(self) -> None: ...
-    def close(self) -> None: ...
-    def fileno(self) -> int: ...
-    def flush(self) -> None: ...
-    def isatty(self) -> bool: ...
-    def next(self) -> str: ...
-    def readable(self) -> bool: ...
-    def readline(self, limit: int = ...) -> str: ...
-    def readlines(self, hint: int = ...) -> List[str]: ...
-    def seek(self, offset: int, whence: int = ...) -> None: ...
-    def seekable(self) -> bool: ...
-    def tell(self) -> int: ...
-    def truncate(self, size: int = ...) -> int: ...
-    def writable(self) -> bool: ...
-    def writelines(self, lines: Iterable[str]) -> None: ...
 
 class _BufferedIOBase(_IOBase):
     def read1(self, n: int) -> str: ...
@@ -87,8 +69,6 @@ class _TextIOBase(_IOBase):
     newlines = ...  # type: Union[str, unicode]
     encoding = ...  # type: Optional[str]
     def read(self, n: int = ...) -> str: ...
-    def write(self) -> None:
-        raise UnsupportedOperation
     def detach(self) -> None:
         raise UnsupportedOperation
 
diff --git a/stdlib/2/io.pyi b/stdlib/2/io.pyi
index 330b9843a..18bf7b593 100644
--- a/stdlib/2/io.pyi
+++ b/stdlib/2/io.pyi
@@ -5,6 +5,7 @@
 # Only a subset of functionality is included.
 
 from typing import List, BinaryIO, TextIO, IO, overload, Iterator, Iterable, Any, Union, Optional
+import _io
 
 DEFAULT_BUFFER_SIZE = 0
 
@@ -13,9 +14,7 @@ def open(file: Union[str, unicode, int],
          errors: unicode = ..., newline: unicode = ...,
          closefd: bool = ...) -> IO[Any]: ...
 
-class IOBase:
-    # TODO
-    ...
+class IOBase(_io._IOBase): ...
 
 class BytesIO(BinaryIO):
     def __init__(self, initial_bytes: str = ...) -> None: ...