Fixed #28908 -- Allowed ArrayField lookups on ArrayAgg annotations.

1 files changed, 5 insertions, 1 deletions

diff --git a/django/contrib/postgres/aggregates/general.py b/django/contrib/postgres/aggregates/general.py
index 471eda2970..806ecd1b78 100644
--- a/django/contrib/postgres/aggregates/general.py
+++ b/django/contrib/postgres/aggregates/general.py
@@ -1,4 +1,4 @@
-from django.contrib.postgres.fields import JSONField
+from django.contrib.postgres.fields import ArrayField, JSONField
 from django.db.models.aggregates import Aggregate
 
 __all__ = [
@@ -10,6 +10,10 @@ class ArrayAgg(Aggregate):
     function = 'ARRAY_AGG'
     template = '%(function)s(%(distinct)s%(expressions)s)'
 
+    @property
+    def output_field(self):
+        return ArrayField(self.source_expressions[0].output_field)
+
     def __init__(self, expression, distinct=False, **extra):
         super().__init__(expression, distinct='DISTINCT ' if distinct else '', **extra)