diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 5a1c30c..ca2274f 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -13,9 +13,8 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
-        # TODO: remove `7.1` in the next release
-        pytest-version: ["~=6.2", "~=7.1", "~=7.2"]
+        python-version: ["3.8", "3.9", "3.10", "3.11"]
+        pytest-version: ["~=6.2", "~=7.2"]
 
     steps:
     - uses: actions/checkout@v3
@@ -40,7 +39,7 @@ jobs:
     - name: Set up Python 3.9
       uses: actions/setup-python@v4
       with:
-        python-version: 3.9
+        python-version: 3.11
     - name: Install dependencies
       run: |
         pip install -U pip setuptools wheel
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c92bc61..64868ff 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,15 +1,18 @@
 # Version history
 
 
-## WIP
+## 3.0.0
 
 ### Features
 
-- Add `tox.ini` file
+- *Breaking*: Drop python3.7 support
+- Add `pyproject.toml` config file support with `--mypy-pyproject-toml-file` option
 
 ### Bugfixes
 
-- Add `requirements.txt` to `sdist` package
+- Add `tox.ini` file to `sdist` package
+- Add `requirements.txt` file to `sdist` package
+- Add `pyproject.toml` file to `sdist` package
 
 
 ## 2.0.0
diff --git a/MANIFEST.in b/MANIFEST.in
index ce56634..94d4346 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,5 +1,4 @@
-include mypy.ini
-include pytest.ini
 include requirements.txt
 include tox.ini
+include pyproject.toml
 graft pytest_mypy_plugins/tests
diff --git a/README.md b/README.md
index 4be152c..4711f28 100644
--- a/README.md
+++ b/README.md
@@ -68,7 +68,7 @@ On top of that, each case must comply to following types:
 | `main`          | `str`                                                  | Portion of the code as if written in `.py` file                                                                     |
 | `files`         | `Optional[List[File]]=[]`\*                            | List of extra files to simulate imports if needed                                                                   |
 | `disable_cache` | `Optional[bool]=False`                                 | Set to `true` disables `mypy` caching                                                                               |
-| `mypy_config`   | `Optional[Dict[str, Union[str, int, bool, float]]]={}` | Inline `mypy` configuration, passed directly to `mypy` as `--config-file` option                                    |
+| `mypy_config`   | `Optional[Dict[str, Union[str, int, bool, float]]]={}` | Inline `mypy` configuration, passed directly to `mypy` as `--config-file` option, possibly joined with `--mypy-pyproject-toml-file` or `--mypy-ini-file` contents if they are passed. By default is treated as `ini`, treated as `toml` only if `--mypy-pyproject-toml-file` is passed |
 | `env`           | `Optional[Dict[str, str]]={}`                          | Environmental variables to be provided inside of test run                                                           |
 | `parametrized`  | `Optional[List[Parameter]]=[]`\*                       | List of parameters, similar to [`@pytest.mark.parametrize`](https://docs.pytest.org/en/stable/parametrize.html)     |
 | `skip`          | `str`                                                  | Expression evaluated with following globals set: `sys`, `os`, `pytest` and `platform`                               |
@@ -170,11 +170,18 @@ Properties that you can parametrize:
 mypy-tests:
   --mypy-testing-base=MYPY_TESTING_BASE
                         Base directory for tests to use
+  --mypy-pyproject-toml-file=MYPY_PYPROJECT_TOML_FILE
+                        Which `pyproject.toml` file to use
+                        as a default config for tests.
+                        Incompatible with `--mypy-ini-file`
   --mypy-ini-file=MYPY_INI_FILE
-                        Which .ini file to use as a default config for tests
-  --mypy-same-process   Run in the same process. Useful for debugging, will create problems with import cache
+                        Which `.ini` file to use as a default config for tests.
+                        Incompatible with `--mypy-pyproject-toml-file`
+  --mypy-same-process   Run in the same process. Useful for debugging,
+                        will create problems with import cache
   --mypy-extension-hook=MYPY_EXTENSION_HOOK
-                        Fully qualified path to the extension hook function, in case you need custom yaml keys. Has to be top-level.
+                        Fully qualified path to the extension hook function,
+                        in case you need custom yaml keys. Has to be top-level
   --mypy-only-local-stub
                         mypy will ignore errors from site-packages
 
diff --git a/mypy.ini b/mypy.ini
deleted file mode 100644
index 9f85b65..0000000
--- a/mypy.ini
+++ /dev/null
@@ -1,13 +0,0 @@
-[mypy]
-ignore_missing_imports = True
-# strict checks
-strict_optional = True
-no_implicit_optional = True
-disallow_any_generics = True
-disallow_untyped_defs = True
-strict_equality = True
-warn_unreachable = True
-warn_no_return = True
-warn_unused_ignores = True
-warn_redundant_casts = True
-warn_unused_configs = True
diff --git a/pyproject.toml b/pyproject.toml
index 12c3940..3e845a8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,23 @@
+[tool.mypy]
+ignore_missing_imports = true
+strict_optional = true
+no_implicit_optional = true
+disallow_any_generics = true
+disallow_untyped_defs = true
+strict_equality = true
+warn_unreachable = true
+warn_no_return = true
+warn_unused_ignores = true
+warn_redundant_casts = true
+warn_unused_configs = true
+
+[tool.pytest.ini_options]
+python_files = "test_*.py"
+addopts = "-s --mypy-extension-hook pytest_mypy_plugins.tests.reveal_type_hook.hook"
+
 [tool.black]
 line-length = 120
+target-version = ["py38", "py39", "py310", "py311"]
 
 [tool.isort]
 include_trailing_comma = true
diff --git a/pytest.ini b/pytest.ini
deleted file mode 100644
index 5a515dc..0000000
--- a/pytest.ini
+++ /dev/null
@@ -1,5 +0,0 @@
-[pytest]
-python_files = test_*.py
-addopts =
-    -s
-    --mypy-extension-hook pytest_mypy_plugins.tests.reveal_type_hook.hook
diff --git a/pytest_mypy_plugins/collect.py b/pytest_mypy_plugins/collect.py
index 249c41e..2b33538 100644
--- a/pytest_mypy_plugins/collect.py
+++ b/pytest_mypy_plugins/collect.py
@@ -3,6 +3,7 @@
 import platform
 import sys
 import tempfile
+from dataclasses import dataclass
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -28,10 +29,10 @@
     from pytest_mypy_plugins.item import YamlTestItem
 
 
+@dataclass
 class File:
-    def __init__(self, path: str, content: str) -> None:
-        self.path = path
-        self.content = content
+    path: str
+    content: str
 
 
 def parse_test_files(test_files: List[Dict[str, Any]]) -> List[File]:
@@ -77,7 +78,7 @@ def construct_mapping(self, node: yaml.MappingNode, deep: bool = False) -> Dict[
         mapping = super().construct_mapping(node, deep=deep)
         # Add 1 so line numbering starts at 1
         starting_line = node.start_mark.line + 1
-        for title_node, contents_node in node.value:
+        for title_node, _contents_node in node.value:
             if title_node.value == "main":
                 starting_line = title_node.start_mark.line + 1
         mapping["__line__"] = starting_line
@@ -172,7 +173,16 @@ def pytest_addoption(parser: Parser) -> None:
     group.addoption(
         "--mypy-testing-base", type=str, default=tempfile.gettempdir(), help="Base directory for tests to use"
     )
-    group.addoption("--mypy-ini-file", type=str, help="Which .ini file to use as a default config for tests")
+    group.addoption(
+        "--mypy-pyproject-toml-file",
+        type=str,
+        help="Which `pyproject.toml` file to use as a default config for tests. Incompatible with `--mypy-ini-file`",
+    )
+    group.addoption(
+        "--mypy-ini-file",
+        type=str,
+        help="Which `.ini` file to use as a default config for tests. Incompatible with `--mypy-pyproject-toml-file`",
+    )
     group.addoption(
         "--mypy-same-process",
         action="store_true",
diff --git a/pytest_mypy_plugins/configs.py b/pytest_mypy_plugins/configs.py
new file mode 100644
index 0000000..7595500
--- /dev/null
+++ b/pytest_mypy_plugins/configs.py
@@ -0,0 +1,59 @@
+from configparser import ConfigParser
+from pathlib import Path
+from textwrap import dedent
+from typing import Final, Optional
+
+import tomlkit
+
+_TOML_TABLE_NAME: Final = "[tool.mypy]"
+
+
+def join_ini_configs(base_ini_fpath: Optional[str], additional_mypy_config: str, execution_path: Path) -> Optional[str]:
+    mypy_ini_config = ConfigParser()
+    if base_ini_fpath:
+        mypy_ini_config.read(base_ini_fpath)
+    if additional_mypy_config:
+        if "[mypy]" not in additional_mypy_config:
+            additional_mypy_config = f"[mypy]\n{additional_mypy_config}"
+        mypy_ini_config.read_string(additional_mypy_config)
+
+    if mypy_ini_config.sections():
+        mypy_config_file_path = execution_path / "mypy.ini"
+        with mypy_config_file_path.open("w") as f:
+            mypy_ini_config.write(f)
+        return str(mypy_config_file_path)
+    return None
+
+
+def join_toml_configs(
+    base_pyproject_toml_fpath: str, additional_mypy_config: str, execution_path: Path
+) -> Optional[str]:
+    if base_pyproject_toml_fpath:
+        with open(base_pyproject_toml_fpath) as f:
+            toml_config = tomlkit.parse(f.read())
+    else:
+        # Emtpy document with `[tool.mypy` empty table,
+        # useful for overrides further.
+        toml_config = tomlkit.document()
+
+    if "tool" not in toml_config or "mypy" not in toml_config["tool"]:  # type: ignore[operator]
+        tool = tomlkit.table(is_super_table=True)
+        tool.append("mypy", tomlkit.table())
+        toml_config.append("tool", tool)
+
+    if additional_mypy_config:
+        if _TOML_TABLE_NAME not in additional_mypy_config:
+            additional_mypy_config = f"{_TOML_TABLE_NAME}\n{dedent(additional_mypy_config)}"
+
+        additional_data = tomlkit.parse(additional_mypy_config)
+        toml_config["tool"]["mypy"].update(  # type: ignore[index, union-attr]
+            additional_data["tool"]["mypy"].value.items(),  # type: ignore[index]
+        )
+
+    mypy_config_file_path = execution_path / "pyproject.toml"
+    with mypy_config_file_path.open("w") as f:
+        # We don't want the whole config file, because it can contain
+        # other sections like `[tool.isort]`, we only need `[tool.mypy]` part.
+        f.write(f"{_TOML_TABLE_NAME}\n")
+        f.write(dedent(toml_config["tool"]["mypy"].as_string()))  # type: ignore[index]
+    return str(mypy_config_file_path)
diff --git a/pytest_mypy_plugins/item.py b/pytest_mypy_plugins/item.py
index fe76dfe..20914a6 100644
--- a/pytest_mypy_plugins/item.py
+++ b/pytest_mypy_plugins/item.py
@@ -4,19 +4,8 @@
 import subprocess
 import sys
 import tempfile
-from configparser import ConfigParser
 from pathlib import Path
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    Dict,
-    List,
-    Optional,
-    TextIO,
-    Tuple,
-    Union,
-    no_type_check,
-)
+from typing import TYPE_CHECKING, Any, Dict, List, Optional, TextIO, Tuple, Union
 
 import py
 import pytest
@@ -31,7 +20,7 @@
 if TYPE_CHECKING:
     from _pytest._code.code import _TracebackStyle
 
-from pytest_mypy_plugins import utils
+from pytest_mypy_plugins import configs, utils
 from pytest_mypy_plugins.collect import File, YamlTestFile
 from pytest_mypy_plugins.utils import (
     OutputMatcher,
@@ -147,10 +136,19 @@ def __init__(
 
         # config parameters
         self.root_directory = self.config.option.mypy_testing_base
+
+        # You cannot use both `.ini` and `pyproject.toml` files at the same time:
+        if self.config.option.mypy_ini_file and self.config.option.mypy_pyproject_toml_file:
+            raise ValueError("Cannot specify both `--mypy-ini-file` and `--mypy-pyproject-toml-file`")
+
         if self.config.option.mypy_ini_file:
             self.base_ini_fpath = os.path.abspath(self.config.option.mypy_ini_file)
         else:
             self.base_ini_fpath = None
+        if self.config.option.mypy_pyproject_toml_file:
+            self.base_pyproject_toml_fpath = os.path.abspath(self.config.option.mypy_pyproject_toml_file)
+        else:
+            self.base_pyproject_toml_fpath = None
         self.incremental_cache_dir = os.path.join(self.root_directory, ".mypy_cache")
 
     def make_test_file(self, file: File) -> None:
@@ -204,8 +202,7 @@ def typecheck_in_new_subprocess(
 
         completed = subprocess.run(
             [mypy_executable, *mypy_cmd_options],
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
+            capture_output=True,
             cwd=os.getcwd(),
             env=self.environment_variables,
         )
@@ -314,25 +311,27 @@ def prepare_mypy_cmd_options(self, execution_path: Path) -> List[str]:
         if not self.disable_cache:
             mypy_cmd_options.extend(["--cache-dir", self.incremental_cache_dir])
 
-        # Merge `self.base_ini_fpath` and `self.additional_mypy_config`
-        # into one file and copy to the typechecking folder:
-        mypy_ini_config = ConfigParser()
-        if self.base_ini_fpath:
-            mypy_ini_config.read(self.base_ini_fpath)
-        if self.additional_mypy_config:
-            additional_config = self.additional_mypy_config
-            if "[mypy]" not in additional_config:
-                additional_config = "[mypy]\n" + additional_config
-            mypy_ini_config.read_string(additional_config)
-
-        if mypy_ini_config.sections():
-            mypy_config_file_path = execution_path / "mypy.ini"
-            with mypy_config_file_path.open("w") as f:
-                mypy_ini_config.write(f)
-            mypy_cmd_options.append(f"--config-file={str(mypy_config_file_path)}")
+        config_file = self.prepare_config_file(execution_path)
+        if config_file:
+            mypy_cmd_options.append(f"--config-file={config_file}")
 
         return mypy_cmd_options
 
+    def prepare_config_file(self, execution_path: Path) -> Optional[str]:
+        # Merge (`self.base_ini_fpath` or `base_pyproject_toml_fpath`)
+        # and `self.additional_mypy_config`
+        # into one file and copy to the typechecking folder:
+        if self.base_pyproject_toml_fpath:
+            return configs.join_toml_configs(
+                self.base_pyproject_toml_fpath, self.additional_mypy_config, execution_path
+            )
+        elif self.base_ini_fpath or self.additional_mypy_config:
+            # We might have `self.base_ini_fpath` set as well.
+            # Or this might be a legacy case: only `mypy_config:` is set in the `yaml` test case.
+            # This means that no real file is provided.
+            return configs.join_ini_configs(self.base_ini_fpath, self.additional_mypy_config, execution_path)
+        return None
+
     def repr_failure(
         self, excinfo: ExceptionInfo[BaseException], style: Optional["_TracebackStyle"] = None
     ) -> Union[str, TerminalRepr]:
@@ -357,10 +356,10 @@ def repr_failure(
         else:
             return super().repr_failure(excinfo, style="native")
 
-    @no_type_check
     def reportinfo(self) -> Tuple[Union[py.path.local, Path, str], Optional[int], str]:
         # To support both Pytest 6.x and 7.x
         path = getattr(self, "path", None) or getattr(self, "fspath")
+        assert path
         return path, None, self.name
 
     def _collect_python_path(
diff --git a/pytest_mypy_plugins/tests/test-mypy-config.yml b/pytest_mypy_plugins/tests/test-mypy-config.yml
new file mode 100644
index 0000000..847e6f7
--- /dev/null
+++ b/pytest_mypy_plugins/tests/test-mypy-config.yml
@@ -0,0 +1,9 @@
+# Also used in `test_explicit_configs.py`
+
+- case: custom_mypy_config_strict_optional_true_set
+  main: |
+    from typing import Optional
+    a: Optional[int] = None
+    a + 1  # should not raise an error
+  mypy_config: |
+    strict_optional = false
diff --git a/pytest_mypy_plugins/tests/test-simple-cases.yml b/pytest_mypy_plugins/tests/test-simple-cases.yml
index deb220e..c0472dc 100644
--- a/pytest_mypy_plugins/tests/test-simple-cases.yml
+++ b/pytest_mypy_plugins/tests/test-simple-cases.yml
@@ -60,15 +60,6 @@
     a.lower()  # E: "int" has no attribute "lower"  [attr-defined]
 
 
-- case: custom_mypy_config_strict_optional_true_set
-  main: |
-    from typing import Optional
-    a: Optional[int] = None
-    a + 1
-  mypy_config: |
-    strict_optional = False
-
-
 - case: skip_incorrect_test_case
   skip: yes
   main: |
@@ -101,4 +92,4 @@
     a = 'abc'
     reveal_type(a)
   out: |
-    main:2: note: Some other message
\ No newline at end of file
+    main:2: note: Some other message
diff --git a/pytest_mypy_plugins/tests/test_configs/mypy1.ini b/pytest_mypy_plugins/tests/test_configs/mypy1.ini
new file mode 100644
index 0000000..4354939
--- /dev/null
+++ b/pytest_mypy_plugins/tests/test_configs/mypy1.ini
@@ -0,0 +1,2 @@
+[mypy]
+show_traceback = true
diff --git a/pytest_mypy_plugins/tests/test_configs/mypy2.ini b/pytest_mypy_plugins/tests/test_configs/mypy2.ini
new file mode 100644
index 0000000..b7db254
--- /dev/null
+++ b/pytest_mypy_plugins/tests/test_configs/mypy2.ini
@@ -0,0 +1 @@
+# Empty
diff --git a/pytest_mypy_plugins/tests/test_configs/pyproject1.toml b/pytest_mypy_plugins/tests/test_configs/pyproject1.toml
new file mode 100644
index 0000000..18da4f3
--- /dev/null
+++ b/pytest_mypy_plugins/tests/test_configs/pyproject1.toml
@@ -0,0 +1,10 @@
+# This file has `[tool.mypy]` existing config
+
+[tool.mypy]
+warn_unused_ignores = true
+pretty = true
+show_error_codes = true
+
+[tool.other]
+# This section should not be copied:
+key = 'value'
diff --git a/pytest_mypy_plugins/tests/test_configs/pyproject2.toml b/pytest_mypy_plugins/tests/test_configs/pyproject2.toml
new file mode 100644
index 0000000..5733143
--- /dev/null
+++ b/pytest_mypy_plugins/tests/test_configs/pyproject2.toml
@@ -0,0 +1 @@
+# This file has no `[tool.mypy]` existing config
diff --git a/pytest_mypy_plugins/tests/test_configs/setup1.cfg b/pytest_mypy_plugins/tests/test_configs/setup1.cfg
new file mode 100644
index 0000000..4354939
--- /dev/null
+++ b/pytest_mypy_plugins/tests/test_configs/setup1.cfg
@@ -0,0 +1,2 @@
+[mypy]
+show_traceback = true
diff --git a/pytest_mypy_plugins/tests/test_configs/setup2.cfg b/pytest_mypy_plugins/tests/test_configs/setup2.cfg
new file mode 100644
index 0000000..b7db254
--- /dev/null
+++ b/pytest_mypy_plugins/tests/test_configs/setup2.cfg
@@ -0,0 +1 @@
+# Empty
diff --git a/pytest_mypy_plugins/tests/test_configs/test_join_toml_configs.py b/pytest_mypy_plugins/tests/test_configs/test_join_toml_configs.py
new file mode 100644
index 0000000..d1f2ab4
--- /dev/null
+++ b/pytest_mypy_plugins/tests/test_configs/test_join_toml_configs.py
@@ -0,0 +1,114 @@
+from pathlib import Path
+from textwrap import dedent
+from typing import Callable, Final, Optional
+
+import pytest
+
+from pytest_mypy_plugins.configs import join_toml_configs
+
+_ADDITIONAL_CONFIG: Final = """
+[tool.mypy]
+pretty = true
+show_error_codes = false
+show_traceback = true
+"""
+
+_ADDITIONAL_CONFIG_NO_TABLE: Final = """
+pretty = true
+show_error_codes = false
+show_traceback = true
+"""
+
+_PYPROJECT1: Final = str(Path(__file__).parent / "pyproject1.toml")
+_PYPROJECT2: Final = str(Path(__file__).parent / "pyproject2.toml")
+
+
+@pytest.fixture
+def execution_path(tmpdir_factory: pytest.TempdirFactory) -> Path:
+    return Path(tmpdir_factory.mktemp("testproject", numbered=True))
+
+
+_AssertFileContents = Callable[[Optional[str], str], None]
+
+
+@pytest.fixture
+def assert_file_contents() -> _AssertFileContents:
+    def factory(filename: Optional[str], expected: str) -> None:
+        assert filename
+
+        expected = dedent(expected).strip()
+        with open(filename) as f:
+            contents = f.read().strip()
+        assert contents == expected
+
+    return factory
+
+
+@pytest.mark.parametrize(
+    "additional_config",
+    [
+        _ADDITIONAL_CONFIG,
+        _ADDITIONAL_CONFIG_NO_TABLE,
+    ],
+)
+def test_join_existing_config(
+    execution_path: Path, assert_file_contents: _AssertFileContents, additional_config: str
+) -> None:
+    filepath = join_toml_configs(_PYPROJECT1, additional_config, execution_path)
+
+    assert_file_contents(
+        filepath,
+        """
+        [tool.mypy]
+        warn_unused_ignores = true
+        pretty = true
+        show_error_codes = false
+        show_traceback = true
+        """,
+    )
+
+
+@pytest.mark.parametrize(
+    "additional_config",
+    [
+        _ADDITIONAL_CONFIG,
+        _ADDITIONAL_CONFIG_NO_TABLE,
+    ],
+)
+def test_join_missing_config(
+    execution_path: Path, assert_file_contents: _AssertFileContents, additional_config: str
+) -> None:
+    filepath = join_toml_configs(_PYPROJECT2, additional_config, execution_path)
+
+    assert_file_contents(
+        filepath,
+        """
+        [tool.mypy]
+        pretty = true
+        show_error_codes = false
+        show_traceback = true
+        """,
+    )
+
+
+def test_join_missing_config1(execution_path: Path, assert_file_contents: _AssertFileContents) -> None:
+    filepath = join_toml_configs(_PYPROJECT1, "", execution_path)
+
+    assert_file_contents(
+        filepath,
+        """
+        [tool.mypy]
+        warn_unused_ignores = true
+        pretty = true
+        show_error_codes = true
+        """,
+    )
+
+
+def test_join_missing_config2(execution_path: Path, assert_file_contents: _AssertFileContents) -> None:
+    filepath = join_toml_configs(_PYPROJECT2, "", execution_path)
+
+    assert_file_contents(
+        filepath,
+        "[tool.mypy]",
+    )
diff --git a/pytest_mypy_plugins/tests/test_explicit_configs.py b/pytest_mypy_plugins/tests/test_explicit_configs.py
new file mode 100644
index 0000000..4e5cafd
--- /dev/null
+++ b/pytest_mypy_plugins/tests/test_explicit_configs.py
@@ -0,0 +1,46 @@
+import subprocess
+from pathlib import Path
+from typing import Final
+
+import pytest
+
+_PYPROJECT1: Final = str(Path(__file__).parent / "test_configs" / "pyproject1.toml")
+_PYPROJECT2: Final = str(Path(__file__).parent / "test_configs" / "pyproject2.toml")
+_MYPYINI1: Final = str(Path(__file__).parent / "test_configs" / "mypy1.ini")
+_MYPYINI2: Final = str(Path(__file__).parent / "test_configs" / "mypy2.ini")
+_SETUPCFG1: Final = str(Path(__file__).parent / "test_configs" / "setup1.cfg")
+_SETUPCFG2: Final = str(Path(__file__).parent / "test_configs" / "setup2.cfg")
+
+_TEST_FILE: Final = str(Path(__file__).parent / "test-mypy-config.yml")
+
+
+@pytest.mark.parametrize("config_file", [_PYPROJECT1, _PYPROJECT2])
+def test_pyproject_toml(config_file: str) -> None:
+    subprocess.check_output(
+        [
+            "pytest",
+            "--mypy-pyproject-toml-file",
+            config_file,
+            _TEST_FILE,
+        ]
+    )
+
+
+@pytest.mark.parametrize(
+    "config_file",
+    [
+        _MYPYINI1,
+        _MYPYINI2,
+        _SETUPCFG1,
+        _SETUPCFG2,
+    ],
+)
+def test_ini_files(config_file: str) -> None:
+    subprocess.check_output(
+        [
+            "pytest",
+            "--mypy-ini-file",
+            config_file,
+            _TEST_FILE,
+        ]
+    )
diff --git a/pytest_mypy_plugins/utils.py b/pytest_mypy_plugins/utils.py
index 929c7ad..fd32d90 100644
--- a/pytest_mypy_plugins/utils.py
+++ b/pytest_mypy_plugins/utils.py
@@ -164,8 +164,8 @@ def _add_aligned_message(s1: str, s2: str, error_message: str) -> str:
         extra = "..."
 
     # Write a chunk of both lines, aligned.
-    error_message += "  E: {}{}\n".format(s1[:maxw], extra)
-    error_message += "  A: {}{}\n".format(s2[:maxw], extra)
+    error_message += f"  E: {s1[:maxw]}{extra}\n"
+    error_message += f"  A: {s2[:maxw]}{extra}\n"
     # Write an indicator character under the different columns.
     error_message += "     "
     # sys.stderr.write('     ')
@@ -208,10 +208,10 @@ def assert_expected_matched_actual(expected: List[OutputMatcher], actual: List[s
     """
 
     def format_mismatched_line(line: str) -> str:
-        return "  {:<45} (diff)".format(str(line))
+        return f"  {str(line):<45} (diff)"
 
     def format_matched_line(line: str, width: int = 100) -> str:
-        return " {}...".format(line[:width]) if len(line) > width else " {}".format(line)
+        return f" {line[:width]}..." if len(line) > width else f" {line}"
 
     def format_error_lines(lines: List[str]) -> str:
         return "\n".join(lines) if lines else "  (empty)"
diff --git a/setup.py b/setup.py
index 79d2403..34cd01b 100644
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,6 @@
 from setuptools import setup
 
-with open("README.md", "r") as f:
+with open("README.md") as f:
     readme = f.read()
 
 dependencies = [
@@ -11,11 +11,12 @@
     "Jinja2",
     "regex",
     "packaging",
+    "tomlkit>=0.11",
 ]
 
 setup(
     name="pytest-mypy-plugins",
-    version="2.0.0",
+    version="3.0.0",
     description="pytest plugin for writing tests for mypy plugins",
     long_description=readme,
     long_description_content_type="text/markdown",
@@ -29,14 +30,14 @@
     # the following makes a plugin available to pytest
     entry_points={"pytest11": ["pytest-mypy-plugins = pytest_mypy_plugins.collect"]},
     install_requires=dependencies,
-    python_requires=">=3.7",
+    python_requires=">=3.8",
     package_data={
         "pytest_mypy_plugins": ["py.typed"],
     },
     classifiers=[
         "Development Status :: 4 - Beta",
         "License :: OSI Approved :: MIT License",
-        "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",