--- a/mercurial/scmutil.py	Sun Oct 09 12:58:22 2016 +0200
+++ b/mercurial/scmutil.py	Sun Oct 09 12:37:10 2016 +0200
@@ -753,7 +753,7 @@
     if no HGRCPATH, use default os-specific path.'''
     global _rcpath
     if _rcpath is None:
-        if 'HGRCPATH' in os.environ:
+        if 'HGRCPATH' in encoding.environ:
             _rcpath = []
             for p in os.environ['HGRCPATH'].split(os.pathsep):
                 if not p: