diff --git a/mercurial/pycompat.py b/mercurial/pycompat.py
--- a/mercurial/pycompat.py
+++ b/mercurial/pycompat.py
@@ -86,7 +86,7 @@
     return _rapply(f, xs)
 
 
-if os.name == r'nt' and sys.version_info >= (3, 6):
+if os.name == r'nt':
     # MBCS (or ANSI) filesystem encoding must be used as before.
     # Otherwise non-ASCII filenames in existing repositories would be
     # corrupted.
@@ -415,7 +415,6 @@
 
         return json.loads(s, *args, **kwargs)
 
-
 else:
     json_loads = json.loads