diff --git a/aiohttp/test_utils.py b/aiohttp/test_utils.py
index fdc63ee9c4d..daa8527e11d 100644
--- a/aiohttp/test_utils.py
+++ b/aiohttp/test_utils.py
@@ -448,7 +448,7 @@ def teardown_test_loop(loop, fast=False):
 
 
 def _create_app_mock():
-    app = mock.Mock()
+    app = mock.MagicMock()
     app._debug = False
     app.on_response_prepare = Signal(app)
     app.on_response_prepare.freeze()
diff --git a/tests/test_test_utils.py b/tests/test_test_utils.py
index a45e7cab753..92d4d7a978c 100644
--- a/tests/test_test_utils.py
+++ b/tests/test_test_utils.py
@@ -189,6 +189,11 @@ def test_make_mocked_request_app():
     assert req.app is app
 
 
+def test_make_mocked_request_app_doesnt_crash_on_key_access():
+    req = make_mocked_request('GET', '/')
+    req.app["accessing this shouldn't crash"]
+
+
 def test_make_mocked_request_match_info():
     req = make_mocked_request('GET', '/', match_info={'a': '1', 'b': '2'})
     assert req.match_info == {'a': '1', 'b': '2'}