diff --git a/beetsplug/duplicates.py b/beetsplug/duplicates.py
index f63a7be20..2584e6628 100644
--- a/beetsplug/duplicates.py
+++ b/beetsplug/duplicates.py
@@ -81,7 +81,7 @@ class DuplicatesPlugin(BeetsPlugin):
             help=u'report duplicates only if all attributes are set',
         )
         self._command.parser.add_option(
-            u'-k', u'--key',
+            u'-k', u'--key', dest='keys',
             action='append', metavar='KEY',
             help=u'report duplicates based on keys (use multiple times)',
         )
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 3574060d2..860f58256 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -45,6 +45,8 @@ 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`: Fix the `--key` command line option, which was
+  ignored.
 
 For developers: