diff --git a/beets/autotag/match.py b/beets/autotag/match.py
index e16b0dfaa..cfe184e71 100644
--- a/beets/autotag/match.py
+++ b/beets/autotag/match.py
@@ -29,6 +29,7 @@ from beets import config
 from beets.util import plurality
 from beets.autotag import hooks
 from beets.util.enumeration import OrderedEnum
+from functools import reduce
 
 # Artist signals that indicate "various artists". These are used at the
 # album level to determine whether a given release is likely a VA
diff --git a/beets/dbcore/query.py b/beets/dbcore/query.py
index d344f9fef..caf380260 100644
--- a/beets/dbcore/query.py
+++ b/beets/dbcore/query.py
@@ -22,6 +22,7 @@ from operator import mul
 from beets import util
 from datetime import datetime, timedelta
 import unicodedata
+from functools import reduce
 
 
 class ParsingError(ValueError):
diff --git a/beetsplug/acousticbrainz.py b/beetsplug/acousticbrainz.py
index 507b3e049..df790b26f 100644
--- a/beetsplug/acousticbrainz.py
+++ b/beetsplug/acousticbrainz.py
@@ -21,6 +21,7 @@ import requests
 import operator
 
 from beets import plugins, ui
+from functools import reduce
 
 ACOUSTIC_BASE = "https://acousticbrainz.org/"
 LEVELS = ["/low-level", "/high-level"]