diff -r d64bb25cf797 Lib/multiprocessing/forkserver.py
--- a/Lib/multiprocessing/forkserver.py	Wed Nov 18 02:45:51 2015 +0000
+++ b/Lib/multiprocessing/forkserver.py	Wed Nov 18 14:15:39 2015 +0200
@@ -154,6 +154,12 @@ def main(listener_fd, alive_r, preload, 
             sys.stdin = open(os.devnull)
         except (OSError, ValueError):
             pass
+    if sys.__stdin__ is not None:
+        try:
+            sys.__stdin__.close()
+        except (OSError, ValueError):
+            pass
+    sys.__stdin__ = sys.stdin
 
     # ignoring SIGCHLD means no need to reap zombie processes
     handler = signal.signal(signal.SIGCHLD, signal.SIG_IGN)
diff -r d64bb25cf797 Lib/multiprocessing/process.py
--- a/Lib/multiprocessing/process.py	Wed Nov 18 02:45:51 2015 +0000
+++ b/Lib/multiprocessing/process.py	Wed Nov 18 14:15:39 2015 +0200
@@ -234,12 +234,20 @@ class BaseProcess(object):
                 context._force_start_method(self._start_method)
             _process_counter = itertools.count(1)
             _children = set()
+
             if sys.stdin is not None:
                 try:
                     sys.stdin.close()
                     sys.stdin = open(os.devnull)
                 except (OSError, ValueError):
                     pass
+            if sys.__stdin__ is not None:
+                try:
+                    sys.__stdin__.close()
+                except (OSError, ValueError):
+                    pass
+            sys.__stdin__ = sys.stdin
+
             old_process = _current_process
             _current_process = self
             try:
diff -r d64bb25cf797 Lib/test/_test_multiprocessing.py
--- a/Lib/test/_test_multiprocessing.py	Wed Nov 18 02:45:51 2015 +0000
+++ b/Lib/test/_test_multiprocessing.py	Wed Nov 18 14:15:39 2015 +0200
@@ -455,13 +455,13 @@ class _TestSubclassingProcess(BaseTestCa
 
     @classmethod
     def _test_stderr_flush(cls, testfn):
-        sys.stderr = open(testfn, 'w')
+        sys.__stderr__ = sys.stderr = open(testfn, 'w')
         1/0 # MARKER
 
 
     @classmethod
     def _test_sys_exit(cls, reason, testfn):
-        sys.stderr = open(testfn, 'w')
+        sys.__stderr__ = sys.stderr = open(testfn, 'w')
         sys.exit(reason)
 
     def test_sys_exit(self):
diff -r d64bb25cf797 Python/import.c
--- a/Python/import.c	Wed Nov 18 02:45:51 2015 +0000
+++ b/Python/import.c	Wed Nov 18 14:15:39 2015 +0200
@@ -463,6 +463,30 @@ PyImport_Cleanup(void)
         Py_DECREF(weaklist);
     }
 
+    for (p = sys_files+2; *p != NULL; p++) {
+        if (Py_VerboseFlag)
+            PySys_WriteStderr("# flush sys.%s\n", *p);
+        value = PyDict_GetItemString(interp->sysdict, *p);
+        if (value != NULL && value != Py_None) {
+            PyObject_CallMethod(value, "flush", "");
+            PyErr_Clear();
+        }
+    }
+    for (p = sys_files; *p != NULL; p++) {
+        if (Py_VerboseFlag)
+            PySys_WriteStderr("# close sys.%s\n", *p);
+        value = PyDict_GetItemString(interp->sysdict, *p);
+        if (value != NULL && value != Py_None) {
+            PyObject_CallMethod(value, "close", "");
+            PyErr_Clear();
+        }
+    }
+    for (p = sys_files; *p != NULL; p++) {
+        if (Py_VerboseFlag)
+            PySys_WriteStderr("# clear sys.%s\n", *p);
+        PyDict_SetItemString(interp->sysdict, *p, Py_None);
+    }
+
     /* Next, delete sys and builtins (in that order) */
     if (Py_VerboseFlag)
         PySys_FormatStderr("# cleanup[3] wiping sys\n");