diff --git a/deal/_runtime/_decorators.py b/deal/_runtime/_decorators.py
index ee5403f4..023e30c4 100644
--- a/deal/_runtime/_decorators.py
+++ b/deal/_runtime/_decorators.py
@@ -62,7 +62,7 @@ def pre(
         exception=exception or _exceptions.PreContractError,
     )
     func = partial(Contracts.attach, 'pres', contract)
-    return func  # type: ignore[return-value]
+    return func
 
 
 def post(
@@ -107,7 +107,7 @@ def post(
         exception=exception or _exceptions.PostContractError,
     )
     func = partial(Contracts.attach, 'posts', contract)
-    return func  # type: ignore[return-value]
+    return func
 
 
 def ensure(
@@ -155,7 +155,7 @@ def ensure(
         exception=exception or _exceptions.PostContractError,
     )
     func = partial(Contracts.attach, 'ensures', contract)
-    return func  # type: ignore[return-value]
+    return func
 
 
 def raises(
@@ -204,7 +204,7 @@ def raises(
         exception=exception or _exceptions.RaisesContractError,
     )
     func = partial(Contracts.attach, 'raises', contract)
-    return func  # type: ignore[return-value]
+    return func
 
 
 def has(
@@ -248,7 +248,7 @@ def has(
         exception=exception,
     )
     func = partial(Contracts.attach_has, patcher)
-    return func  # type: ignore[return-value]
+    return func
 
 
 def reason(
@@ -303,7 +303,7 @@ def reason(
         exception=exception or _exceptions.ReasonContractError,
     )
     func = partial(Contracts.attach, 'reasons', contract)
-    return func  # type: ignore[return-value]
+    return func
 
 
 def inv(
@@ -394,7 +394,7 @@ def example(validator: Callable[[], bool]) -> Callable[[C], C]:
         exception=_exceptions.ExampleContractError,
     )
     func = partial(Contracts.attach, 'examples', contract)
-    return func  # type: ignore[return-value]
+    return func
 
 
 @overload
diff --git a/deal/_runtime/_validators.py b/deal/_runtime/_validators.py
index 14b9cead..f2d3f4de 100644
--- a/deal/_runtime/_validators.py
+++ b/deal/_runtime/_validators.py
@@ -15,8 +15,8 @@
 
 
 if TYPE_CHECKING:
-    Args = tuple[object, ...]   # type: ignore[misc]
-    Kwargs = dict[str, object]  # type: ignore[misc]
+    Args = tuple[object, ...]
+    Kwargs = dict[str, object]
 
 
 @lru_cache(maxsize=16)
diff --git a/deal/_trace.py b/deal/_trace.py
index 6bf3d61a..28968238 100644
--- a/deal/_trace.py
+++ b/deal/_trace.py
@@ -56,6 +56,8 @@ def _collect_trace_results(t: Trace, func, file_name: str, func_result) -> Trace
     last_line = max(all_lines)
 
     covered_lines: set[int] = set()
+    fname: str
+    lineno: int
     for fname, lineno in t.counts:  # type: ignore
         assert fname == file_name
         if lineno < first_line:
diff --git a/pyproject.toml b/pyproject.toml
index 269acc24..fc6f53b7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -111,7 +111,7 @@ has-astroid = "not is_installed('astroid')"
 
 [tool.mypy]
 files = ["deal"]
-python_version = 3.8
+python_version = "3.9"
 plugins = ["deal.mypy"]
 ignore_missing_imports = true
 show_error_codes = true
diff --git a/tests/test_state.py b/tests/test_state.py
index 8aac7ad2..2fb0277b 100644
--- a/tests/test_state.py
+++ b/tests/test_state.py
@@ -1,4 +1,5 @@
 import os
+import warnings
 
 import pytest
 
@@ -138,18 +139,19 @@ def set_env_vars():
 def test_enable__warnings(restore_state, env_vars, set_env_vars, expected):
     os.environ.clear()
     set_env_vars(env_vars)
-    ewarn = RuntimeWarning if expected else None
-    with pytest.warns(ewarn) as warns:
-        deal.enable()
     if expected:
+        with pytest.warns(RuntimeWarning) as warns:
+            deal.enable()
         assert len(warns) == 1
         assert str(warns[0].message) == f'{expected}. Is it intentional?'
     else:
-        assert len(warns) == 0
+        with warnings.catch_warnings():
+            warnings.simplefilter('error')
+            deal.enable()
 
-    with pytest.warns(None) as warns:
+    with warnings.catch_warnings():
+        warnings.simplefilter('error')
         deal.enable(warn=False)
-    assert len(warns) == 0
 
 
 @pytest.mark.parametrize('env_vars, expected', [
@@ -162,15 +164,16 @@ def test_enable__warnings(restore_state, env_vars, set_env_vars, expected):
 def test_disable__warnings(restore_state, env_vars, set_env_vars, expected):
     os.environ.clear()
     set_env_vars(env_vars)
-    ewarn = RuntimeWarning if expected else None
-    with pytest.warns(ewarn) as warns:
-        deal.disable()
     if expected:
+        with pytest.warns(RuntimeWarning) as warns:
+            deal.disable()
         assert len(warns) == 1
         assert str(warns[0].message) == f'{expected}. Is it intentional?'
     else:
-        assert len(warns) == 0
+        with warnings.catch_warnings():
+            warnings.simplefilter('error')
+            deal.disable()
 
-    with pytest.warns(None) as warns:
+    with warnings.catch_warnings():
+        warnings.simplefilter('error')
         deal.disable(warn=False)
-    assert len(warns) == 0