diff --git a/beets/autotag/match.py b/beets/autotag/match.py
index d352a013f..814738cd1 100644
--- a/beets/autotag/match.py
+++ b/beets/autotag/match.py
@@ -357,8 +357,8 @@ def _add_candidate(items, results, info):
         log.debug('No tracks.')
         return
 
-    # Don't duplicate.
-    if info.album_id in results:
+    # Prevent duplicates.
+    if info.album_id and info.album_id in results:
         log.debug('Duplicate.')
         return
 
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 1c7ab25ac..7135ecb3e 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -15,6 +15,9 @@ New features:
 
 Bug fixes:
 
+* The autotagger no longer considers all matches without a MusicBrainz ID as
+  duplicates of each other.
+  :bug:`4299`
 * :doc:`/plugins/convert`: Resize album art when embedding
   :bug:`2116`
 * :doc:`/plugins/deezer`: Fix auto tagger pagination issues (fetch beyond the