diff --git a/tests/test_downloader_handlers.py b/tests/test_downloader_handlers.py
index a8763a7a5..f51a6cd3c 100644
--- a/tests/test_downloader_handlers.py
+++ b/tests/test_downloader_handlers.py
@@ -115,6 +115,7 @@ class FileTestCase(unittest.TestCase):
             self.assertEqual(response.url, request.url)
             self.assertEqual(response.status, 200)
             self.assertEqual(response.body, b'0123456789')
+            self.assertEqual(response.protocol, None)
 
         request = Request(path_to_file_uri(self.tmpname + '^'))
         assert request.url.upper().endswith('%5E')
@@ -976,6 +977,7 @@ class BaseFTPTestCase(unittest.TestCase):
             self.assertEqual(r.status, 200)
             self.assertEqual(r.body, b'I have the power!')
             self.assertEqual(r.headers, {b'Local Filename': [b''], b'Size': [b'17']})
+            self.assertIsNone(r.protocol)
         return self._add_test_callbacks(d, _test)
 
     def test_ftp_download_path_with_spaces(self):
@@ -1134,3 +1136,10 @@ class DataURITestCase(unittest.TestCase):
 
         request = Request('data:text/plain;base64,SGVsbG8sIHdvcmxkLg%3D%3D')
         return self.download_request(request, self.spider).addCallback(_test)
+
+    def test_protocol(self):
+        def _test(response):
+            self.assertIsNone(response.protocol)
+
+        request = Request("data:,")
+        return self.download_request(request, self.spider).addCallback(_test)