diff --git a/django/db/models/sql/subqueries.py b/django/db/models/sql/subqueries.py
index 8beb3fa74a..3f2e4d547f 100644
--- a/django/db/models/sql/subqueries.py
+++ b/django/db/models/sql/subqueries.py
@@ -153,10 +153,7 @@ class UpdateQuery(Query):
 
         Updates are coalesced so that we only run one update query per ancestor.
         """
-        try:
-            self.related_updates[model].append((field, None, value))
-        except KeyError:
-            self.related_updates[model] = [(field, None, value)]
+        self.related_updates.setdefault(model, []).append((field, None, value))
 
     def get_related_updates(self):
         """