diff --git a/aiohttp_session/__init__.py b/aiohttp_session/__init__.py
index d301e2b6..4d238335 100644
--- a/aiohttp_session/__init__.py
+++ b/aiohttp_session/__init__.py
@@ -57,7 +57,7 @@ def __init__(
         new: bool,
         max_age: Optional[int] = None,
     ) -> None:
-        self._changed = False
+        self._changed: bool = False
         self._mapping: Dict[str, Any] = {}
         self._identity = identity if data != {} else None
         self._new = new if data != {} else True
diff --git a/demo/login_required_example.py b/demo/login_required_example.py
index eba7f269..ccb64920 100644
--- a/demo/login_required_example.py
+++ b/demo/login_required_example.py
@@ -30,7 +30,7 @@ async def wrapped(
         # actually load user from your database (e.g. with aiopg)
         user = DATABASE[user_id]
         app["user"] = user
-        return await fn(request, *args, **kwargs)  # type: ignore[call-arg]
+        return await fn(request, *args, **kwargs)
 
     return wrapped
 
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 0025c144..fc8608dd 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -12,7 +12,7 @@ flake8-bugbear==21.11.29
 flake8-import-order==0.18.1
 flake8-requirements==1.5.1
 multidict==5.2.0
-mypy==0.910
+mypy==0.930
 pep257==0.7.0
 pre-commit==2.16.0
 pynacl==1.4.0
diff --git a/tests/test_session_dict.py b/tests/test_session_dict.py
index b6f6ffde..13b329de 100644
--- a/tests/test_session_dict.py
+++ b/tests/test_session_dict.py
@@ -85,7 +85,8 @@ def test_invalidate() -> None:
     s.invalidate()
     assert s == cast(MutableMapping[str, Any], {})
     assert s._changed
-    assert s.created is not None
+    # Mypy bug: https://github.com/python/mypy/issues/11853
+    assert s.created is not None  # type: ignore[unreachable]
 
 
 def test_invalidate2() -> None:
@@ -96,7 +97,8 @@ def test_invalidate2() -> None:
     s.invalidate()
     assert s == cast(MutableMapping[str, Any], {})
     assert s._changed
-    assert s.created is not None
+    # Mypy bug: https://github.com/python/mypy/issues/11853
+    assert s.created is not None  # type: ignore[unreachable]
 
 
 def test_operations() -> None:
@@ -153,5 +155,6 @@ def test_change() -> None:
 
     s.changed()
     assert s._changed
+    # Mypy bug: https://github.com/python/mypy/issues/11853
+    assert s.created == created  # type: ignore[unreachable]
     assert cast(MutableMapping[str, Any], {"a": {"key": "value", "key2": "val2"}}) == s
-    assert s.created == created