diff --git a/flow/record/adapter/broker.py b/flow/record/adapter/broker.py
index 1c3b0431..48d08919 100644
--- a/flow/record/adapter/broker.py
+++ b/flow/record/adapter/broker.py
@@ -3,6 +3,7 @@
 from typing import TYPE_CHECKING
 
 from flow.broker import Publisher, Subscriber
+
 from flow.record.adapter import AbstractReader, AbstractWriter
 
 if TYPE_CHECKING:
diff --git a/flow/record/adapter/csvfile.py b/flow/record/adapter/csvfile.py
index 197abf60..54a4c814 100644
--- a/flow/record/adapter/csvfile.py
+++ b/flow/record/adapter/csvfile.py
@@ -118,7 +118,7 @@ def __iter__(self) -> Iterator[Record]:
         ctx = get_app_context()
         selector = self.selector
         for row in self.reader:
-            rdict = dict(zip(self.fields, row))
+            rdict = dict(zip(self.fields, row, strict=False))
             record = self.desc.init_from_dict(rdict)
             if match_record_with_context(record, selector, ctx):
                 yield record
diff --git a/flow/record/adapter/sqlite.py b/flow/record/adapter/sqlite.py
index 78555a42..a48c83de 100644
--- a/flow/record/adapter/sqlite.py
+++ b/flow/record/adapter/sqlite.py
@@ -192,7 +192,7 @@ def read_table(self, table_name: str) -> Iterator[Record]:
                             row[idx] = None
                         elif isinstance(value, str):
                             row[idx] = value.encode(errors="surrogateescape")
-                yield descriptor_cls.init_from_dict(dict(zip(fnames, row)))
+                yield descriptor_cls.init_from_dict(dict(zip(fnames, row, strict=False)))
 
     def __iter__(self) -> Iterator[Record]:
         """Iterate over all tables in the database and yield records."""
diff --git a/flow/record/adapter/xlsx.py b/flow/record/adapter/xlsx.py
index 069bf463..6a7a6e8a 100644
--- a/flow/record/adapter/xlsx.py
+++ b/flow/record/adapter/xlsx.py
@@ -144,7 +144,7 @@ def __iter__(self) -> Iterator[Record]:
                         for col in row
                         if col.value and not col.value.startswith("_")
                     ]
-                    desc = record.RecordDescriptor(desc_name, list(zip(field_types, field_names)))
+                    desc = record.RecordDescriptor(desc_name, list(zip(field_types, field_names, strict=False)))
                     continue
 
                 record_values = []
diff --git a/flow/record/base.py b/flow/record/base.py
index 527ac39c..0573af7d 100644
--- a/flow/record/base.py
+++ b/flow/record/base.py
@@ -21,7 +21,6 @@
     TYPE_CHECKING,
     Any,
     BinaryIO,
-    Callable,
 )
 from urllib.parse import parse_qsl, urlparse
 
@@ -60,7 +59,7 @@
 from flow.record.whitelist import WHITELIST, WHITELIST_TREE
 
 if TYPE_CHECKING:
-    from collections.abc import Iterator, Mapping, Sequence
+    from collections.abc import Callable, Iterator, Mapping, Sequence
 
     from flow.record.adapter import AbstractReader, AbstractWriter
 
@@ -1000,7 +999,7 @@ def merge_record_descriptors(
             field_map[fname] = ftype
     if name is None and descriptors:
         name = descriptors[0].name
-    return RecordDescriptor(name, zip(field_map.values(), field_map.keys()))
+    return RecordDescriptor(name, zip(field_map.values(), field_map.keys(), strict=False))
 
 
 def extend_record(
diff --git a/flow/record/context.py b/flow/record/context.py
index 740bd5d9..c0211d4f 100644
--- a/flow/record/context.py
+++ b/flow/record/context.py
@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-import sys
 from contextlib import contextmanager
 from contextvars import ContextVar
 from dataclasses import dataclass
@@ -37,15 +36,7 @@ def fresh_app_context() -> Generator[AppContext, None, None]:
         APP_CONTEXT.reset(token)
 
 
-# Use slots=True on dataclass for better performance which requires Python 3.10 or later.
-# This can be removed when we drop support for Python 3.9.
-if sys.version_info >= (3, 10):
-    app_dataclass = dataclass(slots=True)  # novermin
-else:
-    app_dataclass = dataclass
-
-
-@app_dataclass
+@dataclass(slots=True)
 class AppContext:
     """Context for the application, holding metrics like amount of processed records."""
 
diff --git a/flow/record/fieldtypes/net/ip.py b/flow/record/fieldtypes/net/ip.py
index 85965d89..fdf6df88 100644
--- a/flow/record/fieldtypes/net/ip.py
+++ b/flow/record/fieldtypes/net/ip.py
@@ -11,16 +11,15 @@
     ip_interface,
     ip_network,
 )
-from typing import Union
 
 from flow.record.base import FieldType
 from flow.record.fieldtypes import defang
 
-_IPNetwork = Union[IPv4Network, IPv6Network]
-_IPAddress = Union[IPv4Address, IPv6Address]
-_IPInterface = Union[IPv4Interface, IPv6Interface]
-_ConversionTypes = Union[str, int, bytes]
-_IPTypes = Union[_IPNetwork, _IPAddress, _IPInterface]
+_IPNetwork = IPv4Network | IPv6Network
+_IPAddress = IPv4Address | IPv6Address
+_IPInterface = IPv4Interface | IPv6Interface
+_ConversionTypes = str | int | bytes
+_IPTypes = _IPNetwork | _IPAddress | _IPInterface
 
 
 class ipaddress(FieldType):
diff --git a/flow/record/fieldtypes/net/ipv4.py b/flow/record/fieldtypes/net/ipv4.py
index 8397dc02..6701577c 100644
--- a/flow/record/fieldtypes/net/ipv4.py
+++ b/flow/record/fieldtypes/net/ipv4.py
@@ -29,7 +29,7 @@ def addr_str(s: address | int | str) -> str:
 
 
 def mask_to_bits(n: int) -> int:
-    return bin(n).count("1")
+    return n.bit_count()
 
 
 def bits_to_mask(b: int) -> int:
@@ -51,7 +51,7 @@ def __init__(self, addr: str, netmask: int | None = None):
             raise TypeError(f"Subnet() argument 1 must be string, not {type(addr).__name__}")
 
         if netmask is None:
-            ip, sep, mask = addr.partition("/")
+            ip, _, mask = addr.partition("/")
             self.mask = bits_to_mask(int(mask)) if mask else 0xFFFFFFFF
             self.net = addr_long(ip)
         else:
@@ -93,7 +93,7 @@ def __init__(self):
     def load(self, path: str | Path) -> None:
         with Path(path).open() as fh:
             for line in fh:
-                entry, desc = line.split(" ", 1)
+                entry, _ = line.split(" ", 1)
                 self.subnets.append(subnet(entry))
 
     def add(self, entry: str) -> None:
diff --git a/flow/record/selector.py b/flow/record/selector.py
index 42518a94..ee54081a 100644
--- a/flow/record/selector.py
+++ b/flow/record/selector.py
@@ -4,14 +4,14 @@
 import ast
 import operator
 import re
-from typing import TYPE_CHECKING, Any, Callable
+from typing import TYPE_CHECKING, Any
 
 from flow.record.base import GroupedRecord, Record, dynamic_fieldtype
 from flow.record.fieldtypes import net
 from flow.record.whitelist import WHITELIST, WHITELIST_TREE
 
 if TYPE_CHECKING:
-    from collections.abc import Iterator
+    from collections.abc import Callable, Iterator
 
 try:
     import astor
diff --git a/flow/record/utils.py b/flow/record/utils.py
index 857e0d39..89b3a3f2 100644
--- a/flow/record/utils.py
+++ b/flow/record/utils.py
@@ -5,7 +5,10 @@
 import sys
 import warnings
 from functools import wraps
-from typing import Any, BinaryIO, Callable, TextIO
+from typing import TYPE_CHECKING, Any, BinaryIO, TextIO
+
+if TYPE_CHECKING:
+    from collections.abc import Callable
 
 LOGGING_TRACE_LEVEL = 5
 
diff --git a/pyproject.toml b/pyproject.toml
index 0b1ec9c2..2b75e7f2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,7 @@ build-backend = "setuptools.build_meta"
 name = "flow.record"
 description = "A library for defining and creating structured data (called records) that can be streamed to disk or piped to other tools that use flow.record"
 readme = "README.md"
-requires-python = ">=3.9.0"
+requires-python = ">=3.10"
 license = "AGPL-3.0-or-later"
 license-files = ["LICENSE", "COPYRIGHT"]
 authors = [
@@ -37,8 +37,7 @@ repository = "https://github.com/fox-it/flow.record"
 # Note: these compression libraries do not work well with pypy
 compression = [
     "lz4",
-    "zstandard==0.23.0; platform_python_implementation == 'PyPy' and python_version == '3.9'", # Pin to last working for PyPy3.9
-    "zstandard; platform_python_implementation != 'PyPy' and python_version != '3.9'", # Otherwise, pick the latest
+    "zstandard; platform_python_implementation != 'PyPy'",
 ]
 elastic = [
     "elasticsearch",
@@ -47,12 +46,11 @@ geoip = [
     "maxminddb",
 ]
 avro = [
-    "cramjam<2.8.4; platform_python_implementation == 'PyPy' and python_version == '3.9'", # Pin to last working for PyPy3.9
     "fastavro[snappy]",
 ]
 duckdb = [
-    "duckdb",
-    "pytz", # duckdb requires pytz for timezone support
+    "duckdb; platform_python_implementation != 'PyPy'", # Don't install duckdb on PyPy
+    "pytz; platform_python_implementation != 'PyPy'", # Don't install duckdb on PyPy
 ]
 splunk = [
     "httpx",
@@ -66,13 +64,65 @@ full = [
     "structlog",
 ]
 
+# This list is duplicated due to https://github.com/fox-it/flow.record/pull/182#discussion_r2284582481
+[dependency-groups]
+compression = [
+    "lz4",
+    "zstandard; platform_python_implementation != 'PyPy'",
+]
+elastic = [
+    "elasticsearch",
+]
+geoip = [
+    "maxminddb",
+]
+avro = [
+    "fastavro[snappy]",
+]
+duckdb = [
+    "duckdb; platform_python_implementation != 'PyPy'", # Don't install duckdb on PyPy
+    "pytz; platform_python_implementation != 'PyPy'", # Don't install duckdb on PyPy
+]
+splunk = [
+    "httpx",
+]
+xlsx = [
+    "openpyxl",
+]
+test = [
+    {include-group = "compression"},
+    {include-group = "avro"},
+    {include-group = "elastic"},
+    {include-group = "xlsx"},
+    {include-group = "duckdb"},
+    "tqdm",
+    "structlog",
+    "pytest",
+]
+full = [
+    {include-group = "compression"},
+    "tqdm",
+    "structlog",
+]
+build = [
+    "build",
+]
+lint = [
+    "ruff==0.13.1",
+    "vermin",
+]
+dev = [
+    {include-group = "test"},
+    {include-group = "lint"},
+]
+
 [project.scripts]
 rdump = "flow.record.tools.rdump:main"
 rgeoip = "flow.record.tools.geoip:main"
 
 [tool.ruff]
 line-length = 120
-required-version = ">=0.9.0"
+required-version = ">=0.13.1"
 extend-exclude = ["flow/record/version.py"]
 
 [tool.ruff.format]
@@ -127,56 +177,3 @@ include = ["flow.*"]
 [tool.setuptools_scm]
 version_file = "flow/record/version.py"
 
-# This list is duplicated due to https://github.com/fox-it/flow.record/pull/182#discussion_r2284582481
-[dependency-groups]
-compression = [
-    "lz4",
-    "zstandard==0.23.0; platform_python_implementation == 'PyPy' and python_version == '3.9'", # Pin to last working for PyPy3.9
-    "zstandard; platform_python_implementation != 'PyPy' and python_version != '3.9'", # Otherwise, pick the latest
-]
-elastic = [
-    "elasticsearch",
-]
-geoip = [
-    "maxminddb",
-]
-avro = [
-    "cramjam<2.8.4; platform_python_implementation == 'PyPy' and python_version == '3.9'", # Pin to last working for PyPy3.9
-    "fastavro[snappy]",
-]
-duckdb = [
-    "duckdb; platform_python_implementation != 'PyPy'", # Don't install duckdb on PyPy
-    "pytz; platform_python_implementation != 'PyPy'", # Don't install duckdb on PyPy
-]
-splunk = [
-    "httpx",
-]
-xlsx = [
-    "openpyxl",
-]
-test = [
-    {include-group = "compression"},
-    {include-group = "avro"},
-    {include-group = "elastic"},
-    {include-group = "xlsx"},
-    {include-group = "duckdb"},
-    "tqdm",
-    "structlog",
-    "pytest",
-]
-full = [
-    {include-group = "compression"},
-    "tqdm",
-    "structlog",
-]
-build = [
-    "build",
-]
-lint = [
-    "ruff==0.12.9",
-    "vermin",
-]
-dev = [
-    {include-group = "test"},
-    {include-group = "lint"},
-]
diff --git a/tests/adapter/test_splunk.py b/tests/adapter/test_splunk.py
index 9d6ef1d8..933a9d04 100644
--- a/tests/adapter/test_splunk.py
+++ b/tests/adapter/test_splunk.py
@@ -56,7 +56,11 @@ def mock_httpx_package(monkeypatch: pytest.MonkeyPatch) -> Iterator[MagicMock]:
 
 
 @pytest.mark.parametrize(
-    ("field", "escaped"), [*list(zip(escaped_fields, [True] * len(escaped_fields))), ("not_escaped", False)]
+    ("field", "escaped"),
+    [
+        *list(zip(escaped_fields, [True] * len(escaped_fields), strict=False)),
+        ("not_escaped", False),
+    ],
 )
 def test_escape_field_name(field: str, escaped: bool) -> None:
     if escaped:
diff --git a/tests/adapter/test_sqlite_duckdb.py b/tests/adapter/test_sqlite_duckdb.py
index 6a5ab26d..0538c407 100644
--- a/tests/adapter/test_sqlite_duckdb.py
+++ b/tests/adapter/test_sqlite_duckdb.py
@@ -327,7 +327,7 @@ def test_invalid_field_names_quoting(tmp_path: Path, invalid_field_name: str) ->
 
     # However, these field names are invalid in flow.record and should raise an exception
     with (
-        pytest.raises(RecordDescriptorError, match="Field .* is an invalid or reserved field name."),
+        pytest.raises(RecordDescriptorError, match=r"Field .* is an invalid or reserved field name."),
         RecordReader(f"sqlite://{db}") as reader,
     ):
         _ = next(iter(reader))
diff --git a/tests/fieldtypes/test_fieldtypes.py b/tests/fieldtypes/test_fieldtypes.py
index 87411125..c4784b31 100644
--- a/tests/fieldtypes/test_fieldtypes.py
+++ b/tests/fieldtypes/test_fieldtypes.py
@@ -6,7 +6,7 @@
 import posixpath
 import types
 from datetime import datetime, timedelta, timezone
-from typing import Callable
+from typing import TYPE_CHECKING
 
 import pytest
 
@@ -30,6 +30,9 @@
 )
 from flow.record.fieldtypes import datetime as dt
 
+if TYPE_CHECKING:
+    from collections.abc import Callable
+
 UTC = timezone.utc
 
 INT64_MAX = (1 << 63) - 1
@@ -1006,10 +1009,10 @@ def test_datetime_timezone_aware(tmp_path: pathlib.Path, record_filename: str) -
 
 
 def test_datetime_comparisions() -> None:
-    with pytest.raises(TypeError, match=".* compare .*naive"):
+    with pytest.raises(TypeError, match=r".* compare .*naive"):
         assert dt("2023-01-01") > datetime(2022, 1, 1)  # noqa: DTZ001
 
-    with pytest.raises(TypeError, match=".* compare .*naive"):
+    with pytest.raises(TypeError, match=r".* compare .*naive"):
         assert datetime(2022, 1, 1) < dt("2023-01-01")  # noqa: DTZ001
 
     assert dt("2023-01-01") > datetime(2022, 1, 1, tzinfo=UTC)
diff --git a/tests/fieldtypes/test_ip.py b/tests/fieldtypes/test_ip.py
index a1c224ee..e9c17bdb 100644
--- a/tests/fieldtypes/test_ip.py
+++ b/tests/fieldtypes/test_ip.py
@@ -18,7 +18,7 @@ def test_field_ipaddress() -> None:
     a = net.IPAddress("192.168.1.1")
     assert a == "192.168.1.1"
 
-    with pytest.raises(ValueError, match=".* does not appear to be an IPv4 or IPv6 address"):
+    with pytest.raises(ValueError, match=r".* does not appear to be an IPv4 or IPv6 address"):
         net.IPAddress("a.a.a.a")
 
 
@@ -27,7 +27,7 @@ def test_field_ipnetwork() -> None:
     assert a == "192.168.1.0/24"
 
     # Host bits set
-    with pytest.raises(ValueError, match=".* has host bits set"):
+    with pytest.raises(ValueError, match=r".* has host bits set"):
         net.IPNetwork("192.168.1.10/24")
 
 
diff --git a/tests/packer/test_json_packer.py b/tests/packer/test_json_packer.py
index 7a139c5a..025b30d8 100644
--- a/tests/packer/test_json_packer.py
+++ b/tests/packer/test_json_packer.py
@@ -69,7 +69,7 @@ def test_record_descriptor_not_found() -> None:
 
     # create a new packer and try to unpack the bytes
     packer = JsonRecordPacker()
-    with pytest.raises(RecordDescriptorNotFound, match="No RecordDescriptor found for: .*test/descriptor_not_found"):
+    with pytest.raises(RecordDescriptorNotFound, match=r"No RecordDescriptor found for: .*test/descriptor_not_found"):
         packer.unpack(data)
 
 
diff --git a/tests/packer/test_packer.py b/tests/packer/test_packer.py
index 17eadc64..3eaf6e53 100644
--- a/tests/packer/test_packer.py
+++ b/tests/packer/test_packer.py
@@ -269,5 +269,5 @@ def test_record_descriptor_not_found() -> None:
 
     # create a new packer and try to unpack the bytes
     packer = RecordPacker()
-    with pytest.raises(RecordDescriptorNotFound, match="No RecordDescriptor found for: .*test/descriptor_not_found"):
+    with pytest.raises(RecordDescriptorNotFound, match=r"No RecordDescriptor found for: .*test/descriptor_not_found"):
         packer.unpack(data)
diff --git a/tests/record/test_adapter.py b/tests/record/test_adapter.py
index b6cb8b37..45eb80ad 100644
--- a/tests/record/test_adapter.py
+++ b/tests/record/test_adapter.py
@@ -357,13 +357,13 @@ def test_text_record_adapter(capsys: pytest.CaptureFixture) -> None:
         # Format string with existing variables
         rec = TestRecordWithFooBar(name="world", foo="foo", bar="bar")
         writer.write(rec)
-        out, err = capsys.readouterr()
+        out, _ = capsys.readouterr()
         assert out == "Hello world, foo is bar!\n"
 
         # Format string with non-existing variables
         rec = TestRecordWithoutFooBar(name="planet")
         writer.write(rec)
-        out, err = capsys.readouterr()
+        out, _ = capsys.readouterr()
         assert out == "Hello planet, {foo} is {bar}!\n"
 
 
@@ -405,23 +405,23 @@ def test_recordstream_header(tmp_path: Path) -> None:
 def test_recordstream_header_stdout(capsysbinary: pytest.CaptureFixture) -> None:
     with RecordWriter() as writer:
         pass
-    out, err = capsysbinary.readouterr()
+    out, _ = capsysbinary.readouterr()
     assert out == b"\x00\x00\x00\x0f\xc4\rRECORDSTREAM\n"
 
     writer = RecordWriter()
     del writer
-    out, err = capsysbinary.readouterr()
+    out, _ = capsysbinary.readouterr()
     assert out == b""
 
     writer = RecordWriter()
     writer.close()
-    out, err = capsysbinary.readouterr()
+    out, _ = capsysbinary.readouterr()
     assert out == b""
 
     writer = RecordWriter()
     writer.flush()
     writer.close()
-    out, err = capsysbinary.readouterr()
+    out, _ = capsysbinary.readouterr()
     assert out == b"\x00\x00\x00\x0f\xc4\rRECORDSTREAM\n"
 
 
diff --git a/tests/record/test_record.py b/tests/record/test_record.py
index 4a507de2..72b0506f 100644
--- a/tests/record/test_record.py
+++ b/tests/record/test_record.py
@@ -523,7 +523,7 @@ def test_record_replace() -> None:
     assert t4._source == "pytest"
     assert t4._generated == t2._generated
 
-    with pytest.raises(ValueError, match=".*Got unexpected field names:.*foobar.*"):
+    with pytest.raises(ValueError, match=r".*Got unexpected field names:.*foobar.*"):
         t._replace(foobar="keyword does not exist")
 
 
diff --git a/tests/selector/test_selectors.py b/tests/selector/test_selectors.py
index a25935f8..fc7b4b10 100644
--- a/tests/selector/test_selectors.py
+++ b/tests/selector/test_selectors.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import re
 from datetime import datetime, timezone
 
 import pytest
@@ -228,13 +229,15 @@ def test_selector_function_call_whitelisting() -> None:
     assert rec in Selector("'pe32' in lower(r.filetype)")
     # But functions on types are not
     with pytest.raises(
-        Exception, match="Call 'r.filetype.lower' not allowed. No calls other then whitelisted 'global' calls allowed!"
+        Exception,
+        match=re.escape("Call 'r.filetype.lower' not allowed. No calls other then whitelisted 'global' calls allowed!"),
     ):
         assert rec in Selector("'pe' in r.filetype.lower()")
 
     assert rec in Selector("'EXECUTABLE' in upper(r.filetype)")
     with pytest.raises(
-        Exception, match="Call 'r.filetype.upper' not allowed. No calls other then whitelisted 'global' calls allowed!"
+        Exception,
+        match=re.escape("Call 'r.filetype.upper' not allowed. No calls other then whitelisted 'global' calls allowed!"),
     ):
         assert rec in Selector("'EXECUTABLE' in r.filetype.upper()")
 
@@ -251,7 +254,8 @@ def test_selector_function_call_whitelisting() -> None:
 
     # We call net.ipv4 instead of net.ipv4.Subnet, which should fail
     with pytest.raises(
-        Exception, match="Call 'net.ipv4' not allowed. No calls other then whitelisted 'global' calls allowed!"
+        Exception,
+        match=re.escape("Call 'net.ipv4' not allowed. No calls other then whitelisted 'global' calls allowed!"),
     ):
         assert rec in Selector("r.ip in net.ipv4('192.168.1.0/24')")
 
diff --git a/tests/test_regressions.py b/tests/test_regressions.py
index 5a76a20d..810ed9b1 100644
--- a/tests/test_regressions.py
+++ b/tests/test_regressions.py
@@ -9,7 +9,7 @@
 from datetime import datetime, timezone
 from io import BytesIO
 from pathlib import Path
-from typing import Callable
+from typing import TYPE_CHECKING
 from unittest.mock import MagicMock, patch
 
 import msgpack
@@ -34,6 +34,9 @@
 from flow.record.tools import rdump
 from flow.record.utils import is_stdout
 
+if TYPE_CHECKING:
+    from collections.abc import Callable
+
 
 def test_datetime_serialization() -> None:
     packer = RecordPacker()
@@ -435,7 +438,7 @@ def test_grouped_replace() -> None:
     assert replaced_grouped_record._source == "testcase"
 
     # Replacement with non existing field should raise a ValueError
-    with pytest.raises(ValueError, match=".*Got unexpected field names:.*non_existing_field.*"):
+    with pytest.raises(ValueError, match=r".*Got unexpected field names:.*non_existing_field.*"):
         grouped_record._replace(number=100, other="changed", non_existing_field="oops")
 
 
@@ -467,7 +470,7 @@ def test_is_stdout(tmp_path: pathlib.Path, capsysbinary: pytest.CaptureFixture)
     with RecordWriter() as writer:
         assert is_stdout(writer.fp)
 
-    out, err = capsysbinary.readouterr()
+    out, _ = capsysbinary.readouterr()
     assert out.startswith(b"\x00\x00\x00\x0f\xc4\rRECORDSTREAM\n")
 
     with RecordWriter(tmp_path / "output.records") as writer:
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 441ae8de..eeb6cdc9 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -21,5 +21,5 @@ def test_boolean_argument() -> None:
     assert boolean_argument(False) is False
     assert boolean_argument(1) is True
     assert boolean_argument(0) is False
-    with pytest.raises(ValueError, match="Invalid boolean argument: .*"):
+    with pytest.raises(ValueError, match=r"Invalid boolean argument: .*"):
         boolean_argument("maybe")
diff --git a/tests/tools/test_rdump.py b/tests/tools/test_rdump.py
index a9ab376e..64bcad76 100644
--- a/tests/tools/test_rdump.py
+++ b/tests/tools/test_rdump.py
@@ -113,7 +113,7 @@ def test_rdump_format_template(tmp_path: Path) -> None:
     args = ["rdump", str(path), "-f", "TEST: {count},{foo}"]
     print(args)
     res = subprocess.Popen(args, stdout=subprocess.PIPE)
-    stdout, stderr = res.communicate()
+    stdout, _ = res.communicate()
     for i, line in enumerate(stdout.decode().splitlines()):
         assert line == f"TEST: {i},bar"
 
@@ -155,7 +155,7 @@ def test_rdump_json(tmp_path: Path) -> None:
     # dump records as JSON lines
     args = ["rdump", str(record_path), "-w", "jsonfile://-?descriptors=true"]
     process = subprocess.Popen(args, stdout=subprocess.PIPE)
-    stdout, stderr = process.communicate()
+    stdout, _ = process.communicate()
 
     assert process.returncode == 0
 
diff --git a/tox.ini b/tox.ini
index e90b5845..72ab0dd0 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,7 @@ envlist = lint, py3, pypy3
 # requires if they are not available on the host system. This requires the
 # locally installed tox to have a minimum version 3.3.0. This means the names
 # of the configuration options are still according to the tox 3.x syntax.
-minversion = 4.11.4
+minversion = 4.27.0
 # This version of virtualenv will install setuptools version 68.2.2 and pip
 # 23.3.1. These versions fully support python projects defined only through a
 # pyproject.toml file (PEP-517/PEP-518/PEP-621). This pip version also support
@@ -42,7 +42,7 @@ dependency_groups = lint
 commands =
     ruff check flow tests
     ruff format --check flow tests
-    vermin -t=3.9- --no-tips --lint flow tests
+    vermin -t=3.10- --no-tips --lint flow tests
 
 [testenv:docs-build]
 allowlist_externals = make