diff --git a/.gitignore b/.gitignore
index 410cb51..50d06e0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@ __version.py
 .cache
 .eggs
 .tox
+.idea/*
 
 build
 dist
diff --git a/pyproject.toml b/pyproject.toml
index 019ea01..0645dec 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -52,6 +52,7 @@ test = [
   "flake8>=4.0.1",
   "pre-commit>=2.17.0",
   "tox>=3.24.5",
+  "mypy>=1.16.0",
 ]
 
 [project.urls]
@@ -77,3 +78,28 @@ exclude = [
 
 [tool.hatch.build.hooks.vcs]
 version-file = "src/pytest_metadata/__version.py"
+
+[tool.mypy]
+allow_redefinition = false
+allow_untyped_globals = false
+check_untyped_defs = true
+disallow_incomplete_defs = true
+disallow_subclassing_any = true
+disallow_untyped_calls = true
+disallow_untyped_decorators = true
+disallow_untyped_defs = true
+follow_imports = "silent"
+ignore_missing_imports = false
+implicit_reexport = false
+no_implicit_optional = true
+pretty = true
+show_error_codes = true
+strict_equality = true
+warn_no_return = false
+warn_return_any = true
+warn_unreachable = true
+warn_unused_ignores = true
+
+[[tool.mypy.overrides]]
+module = ["_pytest._pluggy.*"]
+ignore_missing_imports = true
diff --git a/src/pytest_metadata/hooks.py b/src/pytest_metadata/hooks.py
index 350d42e..7b11852 100644
--- a/src/pytest_metadata/hooks.py
+++ b/src/pytest_metadata/hooks.py
@@ -1,7 +1,10 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
+from typing import Dict
 
+from pytest import Config
 
-def pytest_metadata(metadata, config):
+
+def pytest_metadata(metadata: Dict, config: Config) -> None:
     """Called after collecting metadata"""
diff --git a/src/pytest_metadata/plugin.py b/src/pytest_metadata/plugin.py
index d4bf9ca..202b334 100644
--- a/src/pytest_metadata/plugin.py
+++ b/src/pytest_metadata/plugin.py
@@ -4,6 +4,9 @@
 import json
 import os
 import platform
+from typing import Dict, Callable
+
+from pytest import PytestPluginManager, Config, Parser
 
 try:
     import _pytest._pluggy as pluggy
@@ -36,27 +39,31 @@
 metadata_key = pytest.StashKey[dict]()
 
 
-def pytest_addhooks(pluginmanager):
+def pytest_addhooks(pluginmanager: PytestPluginManager) -> None:
     from pytest_metadata import hooks
 
     pluginmanager.add_hookspecs(hooks)
 
 
 @pytest.fixture(scope="session")
-def metadata(pytestconfig):
+def metadata(pytestconfig: Config) -> Dict:
     """Provide test session metadata"""
     return pytestconfig.stash[metadata_key]
 
 
 @pytest.fixture(scope="session")
-def include_metadata_in_junit_xml(metadata, pytestconfig, record_testsuite_property):
+def include_metadata_in_junit_xml(
+    metadata: Dict,
+    pytestconfig: Config,
+    record_testsuite_property: Callable[[str, object], None],
+) -> None:
     """Provide test session metadata"""
     metadata_ = pytestconfig.stash[metadata_key]
     for name, value in metadata_.items():
         record_testsuite_property(name, value)
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("pytest-metadata")
     group.addoption(
         "--metadata",
@@ -83,7 +90,7 @@ def pytest_addoption(parser):
 
 
 @pytest.hookimpl(tryfirst=True)
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     config.stash[metadata_key] = {
         "Python": platform.python_version(),
         "Platform": platform.platform(),
@@ -118,13 +125,15 @@ def pytest_configure(config):
     config.hook.pytest_metadata(metadata=config.stash[metadata_key], config=config)
 
 
-def pytest_report_header(config):
+def pytest_report_header(config: Config) -> str | None:
     if config.getoption("verbose") > 0:
         return "metadata: {0}".format(config.stash[metadata_key])
 
 
 @pytest.hookimpl(optionalhook=True)
-def pytest_testnodedown(node):
+def pytest_testnodedown(
+    node: "pytest_xdist.WorkerController",  # noqa: F821
+) -> None:  # type:ignore[name-defined]
     # note that any metadata from remote workers will be replaced with the
     # environment from the final worker to quit
     if hasattr(node, "workeroutput"):
diff --git a/src/pytest_metadata/py.typed b/src/pytest_metadata/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_metadata.py b/tests/test_metadata.py
index 4787755..a057aaf 100644
--- a/tests/test_metadata.py
+++ b/tests/test_metadata.py
@@ -2,12 +2,13 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 import pytest
+from pytest import Pytester, MonkeyPatch
 from xml.etree import ElementTree as ET
 
 pytest_plugins = ("pytester",)
 
 
-def test_metadata(pytester):
+def test_metadata(pytester: Pytester) -> None:
     pytester.makepyfile(
         """
         def test_pass(metadata):
@@ -20,7 +21,7 @@ def test_pass(metadata):
     assert result.ret == 0
 
 
-def test_environment_variables(pytester, monkeypatch):
+def test_environment_variables(pytester: Pytester, monkeypatch: MonkeyPatch) -> None:
     monkeypatch.setenv("JENKINS_URL", "foo")
     monkeypatch.setenv("GIT_COMMIT", "bar")
     pytester.makepyfile(
@@ -34,7 +35,7 @@ def test_pass(metadata):
     assert result.ret == 0
 
 
-def test_additional_metadata(pytester):
+def test_additional_metadata(pytester: Pytester) -> None:
     pytester.makepyfile(
         """
         def test_pass(metadata):
@@ -49,7 +50,7 @@ def test_pass(metadata):
 
 
 @pytest.mark.parametrize("junit_format", ["xunit1", "xunit2"])
-def test_junit_integration(pytester, junit_format):
+def test_junit_integration(pytester: Pytester, junit_format: str) -> None:
     pytester.makepyfile(
         """
         import pytest
@@ -78,7 +79,7 @@ def test_pass():
     assert {"name": "Daffy", "value": "Duck"} in xml_metadata
 
 
-def test_additional_metadata_from_json(pytester):
+def test_additional_metadata_from_json(pytester: Pytester) -> None:
     pytester.makepyfile(
         """
         def test_pass(metadata):
@@ -89,7 +90,7 @@ def test_pass(metadata):
     assert result.ret == 0
 
 
-def test_additional_metadata_from_json_file(pytester):
+def test_additional_metadata_from_json_file(pytester: Pytester) -> None:
     pytester.makepyfile(
         """
         def test_pass(metadata):
@@ -102,7 +103,9 @@ def test_pass(metadata):
     assert result.ret == 0
 
 
-def test_additional_metadata_using_key_values_json_str_and_file(pytester):
+def test_additional_metadata_using_key_values_json_str_and_file(
+    pytester: Pytester,
+) -> None:
     pytester.makepyfile(
         """
         def test_pass(metadata):
@@ -125,7 +128,7 @@ def test_pass(metadata):
     assert result.ret == 0
 
 
-def test_metadata_hook(pytester):
+def test_metadata_hook(pytester: Pytester) -> None:
     pytester.makeconftest(
         """
         import pytest
@@ -144,7 +147,7 @@ def test_pass(metadata):
     assert result.ret == 0
 
 
-def test_report_header(pytester):
+def test_report_header(pytester: Pytester) -> None:
     result = pytester.runpytest()
     assert not any(line.startswith("metadata:") for line in result.stdout.lines)
     result = pytester.runpytest("-v")
diff --git a/tox.ini b/tox.ini
index 032f74a..fb89d9c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py{3.8, 3.9, 3.10, 3.11, 3.12, py3.10}, linting
+envlist = py{3.8, 3.9, 3.10, 3.11, 3.12, py3.10}, linting, typing
 isolated_build = True
 
 [testenv]
@@ -10,8 +10,14 @@ commands = pytest -s -ra --color=yes {posargs}
 [testenv:linting]
 skip_install = True
 basepython = python3
-deps = pre-commit
-commands = pre-commit run --all-files --show-diff-on-failure
+
+[testenv:typing]
+skip_install = True
+basepython = python3
+deps =
+    pytest @ git+https://github.com/pytest-dev/pytest.git
+    mypy
+commands = mypy .
 
 [testenv:devel]
 description = Tests with unreleased deps