diff --git a/mitmproxy/connection.py b/mitmproxy/connection.py
index f18880c92..b7f4ad2f5 100644
--- a/mitmproxy/connection.py
+++ b/mitmproxy/connection.py
@@ -197,7 +197,9 @@ class Client(Connection):
             tls_state = ", tls"
         else:
             tls_state = ""
-        return f"Client({human.format_address(self.peername)}, state={self.state.name.lower()}{tls_state})"
+        state = self.state.name
+        assert state
+        return f"Client({human.format_address(self.peername)}, state={state.lower()}{tls_state})"
 
     @property
     def address(self):  # pragma: no cover
@@ -296,7 +298,9 @@ class Server(Connection):
             local_port = f", src_port={self.sockname[1]}"
         else:
             local_port = ""
-        return f"Server({human.format_address(self.address)}, state={self.state.name.lower()}{tls_state}{local_port})"
+        state = self.state.name
+        assert state
+        return f"Server({human.format_address(self.address)}, state={state.lower()}{tls_state}{local_port})"
 
     def __setattr__(self, name, value):
         if name in ("address", "via"):
diff --git a/tox.ini b/tox.ini
index b41164d32..5f3c0df80 100644
--- a/tox.ini
+++ b/tox.ini
@@ -29,13 +29,13 @@ commands =
 
 [testenv:mypy]
 deps =
-  mypy==0.991
+  mypy==1.0.0
   types-certifi==2021.10.8.3
   types-Flask==1.1.6
   types-Werkzeug==1.0.9
-  types-requests==2.28.11.5
+  types-requests==2.28.11.11
   types-cryptography==3.3.23.2
-  types-pyOpenSSL==22.1.0.2
+  types-pyOpenSSL==23.0.0.2
   -e .[dev]
 
 commands =