2 files changed, 37 insertions, 0 deletions
diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index b932726a2..5d08cbcd5 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -115,6 +115,7 @@ class Query(object):
             entity_wrapper = _QueryEntity
         self._entities = []
         self._primary_entity = None
+        self._has_mapper_entities = False
         for ent in util.to_list(entities):
             entity_wrapper(self, ent)
 
diff --git a/test/orm/test_query.py b/test/orm/test_query.py
index 5f290a255..3ed2e7d7a 100644
--- a/test/orm/test_query.py
+++ b/test/orm/test_query.py
@@ -2195,6 +2195,42 @@ class FilterTest(QueryTest, AssertsCompiledSQL):
         )
 
 
+class HasMapperEntitiesTest(QueryTest):
+    def test_entity(self):
+        User = self.classes.User
+        s = Session()
+
+        q = s.query(User)
+
+        assert q._has_mapper_entities
+
+    def test_cols(self):
+        User = self.classes.User
+        s = Session()
+
+        q = s.query(User.id)
+
+        assert not q._has_mapper_entities
+
+    def test_cols_set_entities(self):
+        User = self.classes.User
+        s = Session()
+
+        q = s.query(User.id)
+
+        q._set_entities(User)
+        assert q._has_mapper_entities
+
+    def test_entity_set_entities(self):
+        User = self.classes.User
+        s = Session()
+
+        q = s.query(User)
+
+        q._set_entities(User.id)
+        assert not q._has_mapper_entities
+
+
 class SetOpsTest(QueryTest, AssertsCompiledSQL):
     __dialect__ = 'default'