diff -Nur a/unittest2/compatibility.py b/unittest2/compatibility.py
--- a/unittest2/compatibility.py	2014-10-29 18:51:58.000000000 +0800
+++ b/unittest2/compatibility.py	2022-03-31 11:21:09.580805329 +0800
@@ -1,4 +1,10 @@
 import collections
+try:
+    from collections import abc
+    collections.MutableMapping = abc.MutableMapping
+except:
+    pass
+
 import os
 import sys