diff -r 16b5df5792a8 -r e995f00a9e9a hgext/win32mbcs.py
--- a/hgext/win32mbcs.py	Mon Dec 19 02:15:24 2016 +0530
+++ b/hgext/win32mbcs.py	Mon Dec 19 02:26:41 2016 +0530
@@ -169,7 +169,7 @@
 def extsetup(ui):
     # TODO: decide use of config section for this extension
     if ((not os.path.supports_unicode_filenames) and
-        (sys.platform != 'cygwin')):
+        (pycompat.sysplatform != 'cygwin')):
         ui.warn(_("[win32mbcs] cannot activate on this platform.\n"))
         return
     # determine encoding for filename