--- requirements.txt.orig	2018-12-08 11:30:14.633258651 -0700

+++ requirements.txt	2018-12-08 11:30:51.118169972 -0700

@@ -2,5 +2,5 @@ pybtex>=0.20

 pybtex>=0.20

 pybtex-docutils>=0.2.0

 Sphinx>=2.0

-oset>=0.1.3

+orderedset>=2.0

--- sphinxcontrib/bibtex/cache.py.orig	2018-11-28 06:47:17.000000000 -0700

+++ sphinxcontrib/bibtex/cache.py	2018-12-08 11:30:14.633258651 -0700

@@ -24,7 +24,7 @@ except ImportError:  # pragma: no cover

 import ast

 import collections

 import copy

-from oset import oset

+from orderedset import OrderedSet

 import re

@@ -200,7 +200,7 @@ class Cache:

         self.bibfiles = {}

         self._bibliographies = collections.defaultdict(dict)

-        self._cited = collections.defaultdict(oset)

+        self._cited = collections.defaultdict(OrderedSet)

         self._enum_count = {}

     def purge(self, docname):