diff --git a/beetsplug/duplicates.py b/beetsplug/duplicates.py
index 3da633116..23b476d19 100644
--- a/beetsplug/duplicates.py
+++ b/beetsplug/duplicates.py
@@ -17,7 +17,7 @@
 import logging
 
 from beets.plugins import BeetsPlugin
-from beets.ui import decargs, print_obj, Subcommand
+from beets.ui import decargs, print_obj, vararg_callback, Subcommand
 
 PLUGIN = 'duplicates'
 log = logging.getLogger('beets')
@@ -35,7 +35,7 @@ def _group_by(objs, keys):
     return counts
 
 
-def _duplicates(objs, keys=['mb_trackid'], full=0):
+def _duplicates(objs, keys, full):
     """Generate triples of MBIDs, duplicate counts, and constituent
     objects.
     """
@@ -55,7 +55,7 @@ class DuplicatesPlugin(BeetsPlugin):
         self.config.add({'count': False})
         self.config.add({'album': False})
         self.config.add({'full': False})
-        self.config.add({'keys': ['mb_trackid']})
+        self.config.add({'keys': ['mb_trackid', 'mb_albumid']})
 
         self._command = Subcommand('duplicates',
                                    help=__doc__,
diff --git a/docs/plugins/duplicates.rst b/docs/plugins/duplicates.rst
index c344d50fc..1aee141f7 100644
--- a/docs/plugins/duplicates.rst
+++ b/docs/plugins/duplicates.rst
@@ -32,8 +32,8 @@ config file::
         album: no
         full: no
 	keys:
-	- mb_trackid
-	- album
+  	  - mb_trackid
+	  - album
 
 or on the command-line::
 
@@ -82,9 +82,9 @@ keys
 
 The ``keys`` option (default: ``mb_trackid``) defines in which track
 or album fields duplicates are to be searched. By default, the plugin
-only uses the musicbrainz track or album ID for this purpose. Using the
-``keys`` option (as a YAML list in the configuration file, or a
-comma-delimited string in the command-line), you can extend this behavior
+uses the musicbrainz track and album IDs for this purpose. Using the
+``keys`` option (as a YAML list in the configuration file, or as
+space-delimited strings in the command-line), you can extend this behavior
 to consider other attributes.
 
 
@@ -113,9 +113,9 @@ The same as the above but include the original album, and show the path::
   beet duplicates -acf '$path'
 
 
-Get rid of false positives arising from the same track existing in different albums::
+Get tracks with the same title, artist, and album::
 
-  beet duplicates -k mb_trackid,album
+  beet duplicates -k title albumartist album
 
 TODO
 ----