--- a/tldp/ldpcollection.py
+++ b/tldp/ldpcollection.py
@@ -6,7 +6,7 @@
 import collections
 
 
-class LDPDocumentCollection(collections.MutableMapping):
+class LDPDocumentCollection(collections.abc.MutableMapping):
     '''a dict-like container for DocumentCollection objects
 
     Intended to be subclassed.
