diff --git a/test/test_demjson.py b/test/test_demjson.py
index a52e667..94d9f55 100644
--- a/test/test_demjson.py
+++ b/test/test_demjson.py
@@ -115,7 +115,10 @@ def rawbytes( byte_list ):
 except ImportError:
     # Python 3 has no UserDict. MutableMapping is close, but must
     # supply own __iter__() and __len__() methods.
-    dict_mixin = collections.MutableMapping
+    try:
+        dict_mixin = collections.abc.MutableMapping
+    except AttributeError:
+        dict_mixin = collections.MutableMapping
 
 # A class that behaves like a dict, but is not a subclass of dict
 class LetterOrdDict(dict_mixin):