diff --git a/changelog.d/214.misc b/changelog.d/214.misc
new file mode 100644
index 00000000..19149774
--- /dev/null
+++ b/changelog.d/214.misc
@@ -0,0 +1 @@
+Upgrade development dependencies fixes #199. Contributed by Omar Mohamed
diff --git a/setup.py b/setup.py
index e4dcdfe1..551eefe5 100755
--- a/setup.py
+++ b/setup.py
@@ -55,11 +55,11 @@ def read(fname):
     ],
     extras_require={
         "dev": [
-            "black==19.10b0",
-            "flake8==3.8.3",
+            "black==20.8b1",
+            "flake8==3.9.0",
             "isort~=5.0",
-            "mypy==0.780",
-            "mypy-zope==0.2.7",
+            "mypy==0.812",
+            "mypy-zope==0.3.0",
             "tox",
         ]
     },
diff --git a/sygnal/helper/proxy/proxy_asyncio.py b/sygnal/helper/proxy/proxy_asyncio.py
index 39f3049b..6f136ada 100644
--- a/sygnal/helper/proxy/proxy_asyncio.py
+++ b/sygnal/helper/proxy/proxy_asyncio.py
@@ -270,7 +270,9 @@ class ProxyingEventLoopWrapper:
     """
 
     def __init__(
-        self, wrapped_loop: asyncio.AbstractEventLoop, proxy_url_str: str,
+        self,
+        wrapped_loop: asyncio.AbstractEventLoop,
+        proxy_url_str: str,
     ):
         """
         Args:
diff --git a/tests/test_apns.py b/tests/test_apns.py
index 5898a0a1..d94b6bf0 100644
--- a/tests/test_apns.py
+++ b/tests/test_apns.py
@@ -205,7 +205,8 @@ def test_expected_badge_only_with_default_payload(self):
         ((notification_req,), _kwargs) = method.call_args
 
         self.assertEqual(
-            {"aps": {"badge": 2}}, notification_req.message,
+            {"aps": {"badge": 2}},
+            notification_req.message,
         )
 
         self.assertEqual({"rejected": []}, resp)
diff --git a/tests/test_httpproxy_asyncio.py b/tests/test_httpproxy_asyncio.py
index d173ddfb..c8b02d62 100644
--- a/tests/test_httpproxy_asyncio.py
+++ b/tests/test_httpproxy_asyncio.py
@@ -225,7 +225,10 @@ def config_setup(self, config):
         self.proxy_context.set_ciphers("DEFAULT")
 
     def make_fake_proxy(
-        self, host: str, port: int, proxy_credentials: Optional[Tuple[str, str]],
+        self,
+        host: str,
+        port: int,
+        proxy_credentials: Optional[Tuple[str, str]],
     ) -> Tuple[EchoProtocol, MockTransport, "Task[Tuple[BaseTransport, Protocol]]"]:
         # Task[Tuple[MockTransport, MockProtocol]]