diff --git a/tests/test_multipart.py b/tests/test_multipart.py
index f03b996f1ec..bd736a261e2 100644
--- a/tests/test_multipart.py
+++ b/tests/test_multipart.py
@@ -170,10 +170,12 @@ def test_read_chunk_without_content_length(self):
 
     def test_read_incomplete_chunk(self):
         stream = Stream(b'')
+
         def prepare(data):
             f = asyncio.Future(loop=self.loop)
             f.set_result(data)
             return f
+
         with mock.patch.object(stream, 'read', side_effect=[
             prepare(b'Hello, '),
             prepare(b'World'),