diff --git a/Lib/os.py b/Lib/os.py
--- a/Lib/os.py
+++ b/Lib/os.py
@@ -30,8 +30,9 @@ import stat as st
 
 # Note:  more names are added to __all__ later.
 __all__ = ["altsep", "curdir", "pardir", "sep", "pathsep", "linesep",
-           "defpath", "name", "path", "devnull",
-           "SEEK_SET", "SEEK_CUR", "SEEK_END"]
+           "defpath", "name", "path", "devnull", "SEEK_SET", "SEEK_CUR",
+           "SEEK_END", "fsencode", "fsdecode", "get_exec_path", "fdopen",
+           "popen", "extsep"]
 
 def _exists(name):
     return name in globals()
@@ -700,6 +701,8 @@ if _exists("fork") and not _exists("spaw
     P_WAIT = 0
     P_NOWAIT = P_NOWAITO = 1
 
+    __all__.extend(["P_WAIT", "P_NOWAIT"])
+
     # XXX Should we support P_DETACH?  I suppose it could fork()**2
     # and close the std I/O streams.  Also, P_OVERLAY is the same
     # as execv*()?