diff -r a9c71d578a1c -r 008d37c4d783 mercurial/__init__.py
--- a/mercurial/__init__.py	Fri Aug 12 11:35:17 2016 +0900
+++ b/mercurial/__init__.py	Sat Aug 13 12:08:23 2016 +0900
@@ -23,7 +23,6 @@
 # Modules that have both Python and C implementations. See also the
 # set of .py files under mercurial/pure/.
 _dualmodules = {
-    'mercurial.base85',
     'mercurial.bdiff',
     'mercurial.diffhelpers',
     'mercurial.mpatch',