diff --git a/mastodon/streaming.py b/mastodon/streaming.py
index 3df3298..4941ace 100644
--- a/mastodon/streaming.py
+++ b/mastodon/streaming.py
@@ -56,7 +56,7 @@ class StreamListener(object):
             line = raw_line.decode('utf-8')
         except UnicodeDecodeError as err:
             six.raise_from(
-                MastodonMalformedEventError("Malformed UTF-8", line),
+                MastodonMalformedEventError("Malformed UTF-8"),
                 err
             )
 
diff --git a/tests/test_streaming.py b/tests/test_streaming.py
index 33a3f9a..ac8e691 100644
--- a/tests/test_streaming.py
+++ b/tests/test_streaming.py
@@ -30,7 +30,18 @@ class Listener(StreamListener):
 
     def handle_stream_(self, lines):
         """Test helper to avoid littering all tests with six.b()."""
-        return self.handle_stream(map(six.b, lines))
+        class MockResponse():
+            def __init__(self, data):
+                self.data = data
+                
+            def iter_content(self, chunk_size):
+                for line in self.data:
+                    for byte in line:
+                        bytearr = bytearray()
+                        bytearr.append(byte)
+                        yield(bytearr)
+                    yield(b'\n')
+        return self.handle_stream(MockResponse(map(six.b, lines)))
 
 
 def test_heartbeat():