diff --git a/django/db/models/expressions.py b/django/db/models/expressions.py
index 30c2f465f0..cb50f73f1d 100644
--- a/django/db/models/expressions.py
+++ b/django/db/models/expressions.py
@@ -1082,6 +1082,11 @@ class Subquery(Expression):
             return clone
         return self
 
+    def get_group_by_cols(self, alias=None):
+        if alias:
+            return [Ref(alias, self)]
+        return []
+
 
 class Exists(Subquery):
     template = 'EXISTS(%(subquery)s)'
diff --git a/tests/aggregation/tests.py b/tests/aggregation/tests.py
index 3820496c9f..a336758f45 100644
--- a/tests/aggregation/tests.py
+++ b/tests/aggregation/tests.py
@@ -8,8 +8,9 @@ from django.db.models import (
     Avg, Count, DecimalField, DurationField, F, FloatField, Func, IntegerField,
     Max, Min, Sum, Value,
 )
-from django.db.models.expressions import Case, When
+from django.db.models.expressions import Case, Exists, OuterRef, Subquery, When
 from django.test import TestCase
+from django.test.testcases import skipUnlessDBFeature
 from django.test.utils import Approximate, CaptureQueriesContext
 from django.utils import timezone
 
@@ -1114,3 +1115,48 @@ class AggregateTestCase(TestCase):
             Book.objects.aggregate(is_book=True)
         with self.assertRaisesMessage(TypeError, msg % ', '.join([str(FloatField()), 'True'])):
             Book.objects.aggregate(FloatField(), Avg('price'), is_book=True)
+
+    def test_aggregation_subquery_annotation(self):
+        """Subquery annotations are excluded from the GROUP BY if they are
+        not explicitly grouped against."""
+        latest_book_pubdate_qs = Book.objects.filter(
+            publisher=OuterRef('pk')
+        ).order_by('-pubdate').values('pubdate')[:1]
+        publisher_qs = Publisher.objects.annotate(
+            latest_book_pubdate=Subquery(latest_book_pubdate_qs),
+        ).annotate(count=Count('book'))
+        with self.assertNumQueries(1) as ctx:
+            list(publisher_qs)
+        self.assertEqual(ctx[0]['sql'].count('SELECT'), 2)
+
+    @skipUnlessDBFeature('supports_subqueries_in_group_by')
+    def test_group_by_subquery_annotation(self):
+        """
+        Subquery annotations are included in the GROUP BY if they are
+        grouped against.
+        """
+        long_books_count_qs = Book.objects.filter(
+            publisher=OuterRef('pk'),
+            pages__gt=400,
+        ).values(
+            'publisher'
+        ).annotate(count=Count('pk')).values('count')
+        long_books_count_breakdown = Publisher.objects.values_list(
+            Subquery(long_books_count_qs, IntegerField()),
+        ).annotate(total=Count('*'))
+        self.assertEqual(dict(long_books_count_breakdown), {None: 1, 1: 4})
+
+    @skipUnlessDBFeature('supports_subqueries_in_group_by')
+    def test_group_by_exists_annotation(self):
+        """
+        Exists annotations are included in the GROUP BY if they are
+        grouped against.
+        """
+        long_books_qs = Book.objects.filter(
+            publisher=OuterRef('pk'),
+            pages__gt=800,
+        )
+        has_long_books_breakdown = Publisher.objects.values_list(
+            Exists(long_books_qs),
+        ).annotate(total=Count('*'))
+        self.assertEqual(dict(has_long_books_breakdown), {True: 2, False: 3})