diff --git a/beetsplug/duplicates.py b/beetsplug/duplicates.py
index 6913aaef6..b316cfda6 100644
--- a/beetsplug/duplicates.py
+++ b/beetsplug/duplicates.py
@@ -258,14 +258,14 @@ class DuplicatesPlugin(BeetsPlugin):
         if tiebreak and kind in tiebreak.keys():
             key = lambda x: tuple(getattr(x, k) for k in tiebreak[kind])
         else:
-            if kind is 'items':
+            if kind == 'items':
                 def truthy(v):
                     # Avoid a Unicode warning by avoiding comparison
                     # between a bytes object and the empty Unicode
                     # string ''.
                     return v is not None and \
                         (v != '' if isinstance(v, six.text_type) else True)
-                fields = kind.all_keys()
+                fields = Item.all_keys()
                 key = lambda x: sum(1 for f in fields if truthy(getattr(x, f)))
             else:
                 key = lambda x: len(x.items())
diff --git a/docs/changelog.rst b/docs/changelog.rst
index edeaf8140..8752ff910 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -70,6 +70,8 @@ Fixes:
   Python 3 on Windows with non-ASCII filenames. :bug:`2671`
 * :doc:`/plugins/absubmit`: Fix an occasional crash on Python 3 when the AB
   analysis tool produced non-ASCII metadata. :bug:`2673`
+* :doc:`/plugins/duplicates`: Use default tiebreak for any kind (item/album) that
+  does not have a tiebreak specified in the configuration.
 * :doc:`/plugins/duplicates`: Fix the `--key` command line option, which was
   ignored.
 * :doc:`/plugins/replaygain`: Fix album replaygain calculation with the