diff --git a/sanic/__version__.py b/sanic/__version__.py
index 4410ae56..d9f9ee85 100644
--- a/sanic/__version__.py
+++ b/sanic/__version__.py
@@ -1 +1 @@
-__version__ = "19.12.2"
+__version__ = "19.12.3"
diff --git a/sanic/response.py b/sanic/response.py
index 03f7bea8..4db94fc5 100644
--- a/sanic/response.py
+++ b/sanic/response.py
@@ -22,6 +22,9 @@ except ImportError:
 
 
 class BaseHTTPResponse:
+    def __init__(self):
+        self.asgi = False
+
     def _encode_body(self, data):
         try:
             # Try to encode it regularly
@@ -59,6 +62,8 @@ class StreamingHTTPResponse(BaseHTTPResponse):
         content_type="text/plain",
         chunked=True,
     ):
+        super().__init__()
+
         self.content_type = content_type
         self.streaming_fn = streaming_fn
         self.status = status
@@ -146,6 +151,8 @@ class HTTPResponse(BaseHTTPResponse):
         content_type=None,
         body_bytes=b"",
     ):
+        super().__init__()
+
         self.content_type = content_type
 
         if body is not None:
diff --git a/setup.py b/setup.py
index 019769cf..e762a088 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,6 @@ import codecs
 import os
 import re
 import sys
-
 from distutils.util import strtobool
 
 from setuptools import setup
@@ -39,9 +38,7 @@ def open_local(paths, mode="r", encoding="utf8"):
 
 with open_local(["sanic", "__version__.py"], encoding="latin1") as fp:
     try:
-        version = re.findall(
-            r"^__version__ = \"([^']+)\"\r?$", fp.read(), re.M
-        )[0]
+        version = re.findall(r"^__version__ = \"([^']+)\"\r?$", fp.read(), re.M)[0]
     except IndexError:
         raise RuntimeError("Unable to determine version.")
 
@@ -71,9 +68,7 @@ setup_kwargs = {
     ],
 }
 
-env_dependency = (
-    '; sys_platform != "win32" ' 'and implementation_name == "cpython"'
-)
+env_dependency = '; sys_platform != "win32" ' 'and implementation_name == "cpython"'
 ujson = "ujson>=1.35" + env_dependency
 uvloop = "uvloop>=0.5.3" + env_dependency
 
@@ -83,13 +78,13 @@ requirements = [
     ujson,
     "aiofiles>=0.3.0",
     "websockets>=7.0,<9.0",
-    "multidict>=4.0,<5.0",
+    "multidict==5.0.0",
     "httpx==0.9.3",
 ]
 
 tests_require = [
     "pytest==5.2.1",
-    "multidict>=4.0,<5.0",
+    "multidict==5.0.0",
     "gunicorn",
     "pytest-cov",
     "httpcore==0.3.0",