diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index b5757483..2300f57f 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -44,6 +44,11 @@ repos:
         additional_dependencies:
           - eslint@7.13.0
         args: [src]
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v0.790
+    hooks:
+      - id: mypy
+        files: ^(src/pytest_html|testing)
   - repo: local
     hooks:
       - id: rst
diff --git a/setup.cfg b/setup.cfg
index 526aeb28..9629125b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,2 +1,19 @@
 [bdist_wheel]
 universal = 0
+
+[mypy]
+check_untyped_defs = True
+disallow_any_generics = True
+disallow_incomplete_defs = True
+disallow_untyped_calls = True
+disallow_untyped_decorators = True
+disallow_untyped_defs = True
+ignore_missing_imports = True
+no_implicit_optional = True
+no_implicit_reexport = True
+show_error_codes = True
+strict_equality = True
+warn_redundant_casts = True
+warn_return_any = True
+warn_unreachable = True
+warn_unused_configs = True
diff --git a/src/pytest_html/__init__.py b/src/pytest_html/__init__.py
index 4dcb81e2..e6f80ef5 100644
--- a/src/pytest_html/__init__.py
+++ b/src/pytest_html/__init__.py
@@ -1,5 +1,5 @@
 try:
-    from . import __version
+    from . import __version  # type: ignore
 
     __version__ = __version.version
 except ImportError:
diff --git a/src/pytest_html/extras.py b/src/pytest_html/extras.py
index f64a0eb5..abf7e4c8 100644
--- a/src/pytest_html/extras.py
+++ b/src/pytest_html/extras.py
@@ -1,6 +1,8 @@
 # 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 typing import Optional
 
 FORMAT_HTML = "html"
 FORMAT_IMAGE = "image"
@@ -10,7 +12,13 @@
 FORMAT_VIDEO = "video"
 
 
-def extra(content, format_type, name=None, mime_type=None, extension=None):
+def extra(
+    content: str,
+    format_type: str,
+    name: Optional[str] = None,
+    mime_type: Optional[str] = None,
+    extension: Optional[str] = None,
+) -> Dict[str, Optional[str]]:
     return {
         "name": name,
         "format_type": format_type,
@@ -20,41 +28,51 @@ def extra(content, format_type, name=None, mime_type=None, extension=None):
     }
 
 
-def html(content):
+def html(content: str) -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_HTML)
 
 
-def image(content, name="Image", mime_type="image/png", extension="png"):
+def image(
+    content: str,
+    name: str = "Image",
+    mime_type: str = "image/png",
+    extension: str = "png",
+) -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_IMAGE, name, mime_type, extension)
 
 
-def png(content, name="Image"):
+def png(content: str, name: str = "Image") -> Dict[str, Optional[str]]:
     return image(content, name, mime_type="image/png", extension="png")
 
 
-def jpg(content, name="Image"):
+def jpg(content: str, name: str = "Image") -> Dict[str, Optional[str]]:
     return image(content, name, mime_type="image/jpeg", extension="jpg")
 
 
-def svg(content, name="Image"):
+def svg(content: str, name: str = "Image") -> Dict[str, Optional[str]]:
     return image(content, name, mime_type="image/svg+xml", extension="svg")
 
 
-def json(content, name="JSON"):
+def json(content: str, name: str = "JSON") -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_JSON, name, "application/json", "json")
 
 
-def text(content, name="Text"):
+def text(content: str, name: str = "Text") -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_TEXT, name, "text/plain", "txt")
 
 
-def url(content, name="URL"):
+def url(content: str, name: str = "URL") -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_URL, name)
 
 
-def video(content, name="Video", mime_type="video/mp4", extension="mp4"):
+def video(
+    content: str,
+    name: str = "Video",
+    mime_type: str = "video/mp4",
+    extension: str = "mp4",
+) -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_VIDEO, name, mime_type, extension)
 
 
-def mp4(content, name="Video"):
+def mp4(content: str, name: str = "Video") -> Dict[str, Optional[str]]:
     return video(content, name)
diff --git a/src/pytest_html/hooks.py b/src/pytest_html/hooks.py
index 7b75120b..da1daf4f 100644
--- a/src/pytest_html/hooks.py
+++ b/src/pytest_html/hooks.py
@@ -1,6 +1,7 @@
 # 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/.
+# type: ignore
 
 
 def pytest_html_report_title(report):
diff --git a/src/pytest_html/html_report.py b/src/pytest_html/html_report.py
index e1aa3973..ee5106ca 100644
--- a/src/pytest_html/html_report.py
+++ b/src/pytest_html/html_report.py
@@ -1,3 +1,4 @@
+# type: ignore
 import bisect
 import datetime
 import json
diff --git a/src/pytest_html/outcome.py b/src/pytest_html/outcome.py
index 1bb71acd..8056bb72 100644
--- a/src/pytest_html/outcome.py
+++ b/src/pytest_html/outcome.py
@@ -1,8 +1,17 @@
+from typing import Optional
+
 from py.xml import html
 
 
 class Outcome:
-    def __init__(self, outcome, total=0, label=None, test_result=None, class_html=None):
+    def __init__(
+        self,
+        outcome: str,
+        total: int = 0,
+        label: Optional[str] = None,
+        test_result: Optional[str] = None,
+        class_html: Optional[str] = None,
+    ) -> None:
         self.outcome = outcome
         self.label = label or outcome
         self.class_html = class_html or outcome
@@ -12,7 +21,7 @@ def __init__(self, outcome, total=0, label=None, test_result=None, class_html=No
         self.generate_checkbox()
         self.generate_summary_item()
 
-    def generate_checkbox(self):
+    def generate_checkbox(self) -> None:
         checkbox_kwargs = {"data-test-result": self.test_result.lower()}
         if self.total == 0:
             checkbox_kwargs["disabled"] = "true"
@@ -27,7 +36,7 @@ def generate_checkbox(self):
             **checkbox_kwargs,
         )
 
-    def generate_summary_item(self):
+    def generate_summary_item(self) -> None:
         self.summary_item = html.span(
             f"{self.total} {self.label}", class_=self.class_html
         )
diff --git a/src/pytest_html/plugin.py b/src/pytest_html/plugin.py
index 6a0ef7a4..4d68bb14 100644
--- a/src/pytest_html/plugin.py
+++ b/src/pytest_html/plugin.py
@@ -1,6 +1,7 @@
 # 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/.
+# type: ignore
 import os
 
 import pytest
diff --git a/src/pytest_html/result.py b/src/pytest_html/result.py
index f791e6d7..9748ac61 100644
--- a/src/pytest_html/result.py
+++ b/src/pytest_html/result.py
@@ -1,3 +1,4 @@
+# type: ignore
 import json
 import os
 import re
diff --git a/src/pytest_html/util.py b/src/pytest_html/util.py
index 37259ec7..ae65c4a6 100644
--- a/src/pytest_html/util.py
+++ b/src/pytest_html/util.py
@@ -1,12 +1,14 @@
 import importlib
 from functools import lru_cache
+from types import ModuleType
+from typing import Optional
 
 
 @lru_cache()
-def ansi_support():
+def ansi_support() -> Optional[ModuleType]:
     try:
         # from ansi2html import Ansi2HTMLConverter, style  # NOQA
         return importlib.import_module("ansi2html")
     except ImportError:
         # ansi2html is not installed
-        pass
+        return None
diff --git a/testing/test_pytest_html.py b/testing/test_pytest_html.py
index b2d23af9..b163891a 100644
--- a/testing/test_pytest_html.py
+++ b/testing/test_pytest_html.py
@@ -1,6 +1,7 @@
 # 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/.
+# type: ignore
 import builtins
 import json
 import os