diff --git a/django/db/models/expressions.py b/django/db/models/expressions.py
index 4ce869d80a..44c687ffa7 100644
--- a/django/db/models/expressions.py
+++ b/django/db/models/expressions.py
@@ -960,10 +960,13 @@ class Subquery(Expression):
     def __init__(self, queryset, output_field=None, **extra):
         self.queryset = queryset
         self.extra = extra
-        if output_field is None and len(self.queryset.query.select) == 1:
-            output_field = self.queryset.query.select[0].field
         super().__init__(output_field)
 
+    def _resolve_output_field(self):
+        if len(self.queryset.query.select) == 1:
+            return self.queryset.query.select[0].field
+        return super()._resolve_output_field()
+
     def copy(self):
         clone = super().copy()
         clone.queryset = clone.queryset.all()
diff --git a/docs/releases/2.0.4.txt b/docs/releases/2.0.4.txt
index dcfcc42f47..222b2360a5 100644
--- a/docs/releases/2.0.4.txt
+++ b/docs/releases/2.0.4.txt
@@ -9,4 +9,5 @@ Django 2.0.4 fixes several bugs in 2.0.3.
 Bugfixes
 ========
 
-* ...
+* Fixed a crash when filtering with an ``Exists()`` annotation of a queryset
+  containing a single field (:ticket:`29195`).
diff --git a/tests/expressions/tests.py b/tests/expressions/tests.py
index 0286a956e6..7453838839 100644
--- a/tests/expressions/tests.py
+++ b/tests/expressions/tests.py
@@ -417,6 +417,10 @@ class BasicExpressionsTests(TestCase):
         outer = Employee.objects.annotate(is_point_of_contact=Exists(inner))
         self.assertIs(outer.exists(), True)
 
+    def test_exist_single_field_output_field(self):
+        queryset = Company.objects.values('pk')
+        self.assertIsInstance(Exists(queryset).output_field, models.BooleanField)
+
     def test_subquery(self):
         Company.objects.filter(name='Example Inc.').update(
             point_of_contact=Employee.objects.get(firstname='Joe', lastname='Smith'),