Index: Lib/test/test_doctest.py
===================================================================
--- Lib/test/test_doctest.py	(revision 83356)
+++ Lib/test/test_doctest.py	(working copy)
@@ -2156,8 +2156,18 @@
          >>> suite.run(unittest.TestResult())
          <unittest.result.TestResult run=3 errors=0 failures=2>
 
-       """
 
+       The full filesystem path of the file suite may contain high-bit
+       characters:
+
+         >>> try:
+         ...     suite = doctest.DocFileSuite('./foo_石田リチャード/bar.txt')
+         ... except IOError:
+         ...     pass
+         ...
+
+    """
+
 def test_trailing_space_in_test():
     """
     Trailing spaces in expected output are significant: