diff -r ee3872c14ab3 -r 7b14d649af1b mercurial/mail.py
--- a/mercurial/mail.py	Tue Nov 19 23:19:57 2019 +0900
+++ b/mercurial/mail.py	Tue Nov 19 23:49:05 2019 +0900
@@ -36,7 +36,7 @@
     stringutil,
 )
 
-if not globals():  # hide this from non-pytype users
+if pycompat.TYPE_CHECKING:
     from typing import Any, List, Tuple, Union
 
     # keep pyflakes happy