--- a/hgext/win32mbcs.py	Tue May 09 15:08:47 2017 +0200
+++ b/hgext/win32mbcs.py	Fri May 12 21:46:14 2017 +0900
@@ -155,7 +155,8 @@
 # These functions are required to be called with local encoded string
 # because they expects argument is local encoded string and cause
 # problem with unicode string.
-rfuncs = '''mercurial.encoding.upper mercurial.encoding.lower'''
+rfuncs = '''mercurial.encoding.upper mercurial.encoding.lower
+ mercurial.pycompat.bytestr'''
 
 # List of Windows specific functions to be wrapped.
 winfuncs = '''os.path.splitunc'''