diff --git a/beetsplug/duplicates.py b/beetsplug/duplicates.py
index 991fec935..a8ad4ac90 100644
--- a/beetsplug/duplicates.py
+++ b/beetsplug/duplicates.py
@@ -271,7 +271,7 @@ class DuplicatesPlugin(BeetsPlugin):
 
         Return same number of items, with the head item modified.
         """
-        fields = [f for sublist in Item.get_fields() for f in sublist]
+        fields = Item.all_keys()
         for f in fields:
             for o in objs[1:]:
                 if getattr(objs[0], f, None) in (None, ''):
diff --git a/docs/changelog.rst b/docs/changelog.rst
index eb423079e..ac4202561 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -30,6 +30,7 @@ Fixes:
   (as well as with the explicit command). :bug:`1662` :bug:`1675`
 * :doc:`/plugins/metasync`: Fix a crash when syncing with recent versions of
   iTunes. :bug:`1700`
+* :doc:`/plugins/duplicates`: Fix a crash when merging items. :bug:`1699`
 
 
 1.3.15 (October 17, 2015)