Index: Misc/NEWS
===================================================================
--- Misc/NEWS	(revision 78337)
+++ Misc/NEWS	(working copy)
@@ -21,6 +21,9 @@
 Library
 -------
 
+- Issue #1708316: doctest fix: set the .encoding attribute on the object
+  that doctest uses to replace sys.stdout.
+
 - Issue #7970: email.Generator.flatten now correctly flattens message/rfc822
   messages parsed by email.Parser.HeaderParser.
 
Index: Lib/doctest.py
===================================================================
--- Lib/doctest.py	(revision 78337)
+++ Lib/doctest.py	(working copy)
@@ -1120,6 +1120,7 @@
 
         # Create a fake output target for capturing doctest output.
         self._fakeout = _SpoofOut()
+        self._fakeout.encoding = sys.__stdout__.encoding
 
     #/////////////////////////////////////////////////////////////////
     # Reporting methods