diff --git a/stdlib/2.7/os/__init__.pyi b/stdlib/2.7/os/__init__.pyi
index 105d9dfe6..da49f10f1 100644
--- a/stdlib/2.7/os/__init__.pyi
+++ b/stdlib/2.7/os/__init__.pyi
@@ -141,7 +141,8 @@ def unlink(path: unicode) -> None: ...
 def utime(path: unicode, times: Optional[Tuple[int, int]]) -> None: ...
 
 def abort() -> None: ...
-# TODO: exec*, _exit, EX_*
+# TODO: exec*, EX_*
+def _exit(n: int) -> None: ...
 
 def fork() -> int:
     raise OSError()