diff --git a/django/db/models/query.py b/django/db/models/query.py
index 7d41fe1ca6..5969ab128c 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -625,7 +625,7 @@ class QuerySet(object):
                                  % arg.default_alias)
             kwargs[arg.default_alias] = arg
 
-        names = set([f.name for f in self.model._meta.fields])
+        names = set(self.model._meta.get_all_field_names())
         for aggregate in kwargs:
             if aggregate in names:
                 raise ValueError("The %s annotation conflicts with a field on "
diff --git a/tests/regressiontests/aggregation_regress/tests.py b/tests/regressiontests/aggregation_regress/tests.py
index 786431420d..58d0b2748f 100644
--- a/tests/regressiontests/aggregation_regress/tests.py
+++ b/tests/regressiontests/aggregation_regress/tests.py
@@ -489,6 +489,14 @@ class AggregationTests(TestCase):
         # Regression for #11256 - providing an aggregate name that conflicts with a field name on the model raises ValueError
         self.assertRaises(ValueError, Author.objects.annotate, age=Avg('friends__age'))
 
+    def test_m2m_name_conflict(self):
+        # Regression for #11256 - providing an aggregate name that conflicts with an m2m name on the model raises ValueError
+        self.assertRaises(ValueError, Author.objects.annotate, friends=Count('friends'))
+
+    def test_reverse_relation_name_conflict(self):
+        # Regression for #11256 - providing an aggregate name that conflicts with a reverse-related name on the model raises ValueError
+        self.assertRaises(ValueError, Author.objects.annotate, book_contact_set=Avg('friends__age'))
+
     def test_pickle(self):
         # Regression for #10197 -- Queries with aggregates can be pickled.
         # First check that pickling is possible at all. No crash = success