diff --git a/tests/queries/test_qs_combinators.py b/tests/queries/test_qs_combinators.py
index d034261e64..c93ce80300 100644
--- a/tests/queries/test_qs_combinators.py
+++ b/tests/queries/test_qs_combinators.py
@@ -109,6 +109,15 @@ class QuerySetSetOperationTests(TestCase):
         qs2 = Number.objects.filter(num__gte=2, num__lte=3)
         self.assertNumbersEqual(qs1.union(qs2).order_by('-num'), [3, 2, 1, 0])
 
+    def test_ordering_by_alias(self):
+        qs1 = Number.objects.filter(num__lte=1).values(alias=F('num'))
+        qs2 = Number.objects.filter(num__gte=2, num__lte=3).values(alias=F('num'))
+        self.assertQuerysetEqual(
+            qs1.union(qs2).order_by('-alias'),
+            [3, 2, 1, 0],
+            operator.itemgetter('alias'),
+        )
+
     def test_ordering_by_f_expression(self):
         qs1 = Number.objects.filter(num__lte=1)
         qs2 = Number.objects.filter(num__gte=2, num__lte=3)
@@ -242,6 +251,8 @@ class QuerySetSetOperationTests(TestCase):
         # 'num' got realiased to num2
         with self.assertRaisesMessage(DatabaseError, msg):
             list(qs1.union(qs2).order_by('num'))
+        with self.assertRaisesMessage(DatabaseError, msg):
+            list(qs1.union(qs2).order_by(F('num')))
         # switched order, now 'exists' again:
         list(qs2.union(qs1).order_by('num'))