diff --git a/ament_index_python/ament_index_python/cli.py b/ament_index_python/ament_index_python/cli.py
index 4fa8f67..775eeea 100644
--- a/ament_index_python/ament_index_python/cli.py
+++ b/ament_index_python/ament_index_python/cli.py
@@ -27,11 +27,11 @@ def main(argv: List[str] = sys.argv[1:]) -> Optional[str]:
     arg = parser.add_argument(
         'resource_type', nargs='?', metavar='TYPE',
         help='The type of the resource')
-    arg.completer = resource_type_completer
+    arg.completer = resource_type_completer  # type: ignore[attr-defined]
     arg = parser.add_argument(
         'resource_name', nargs='?', metavar='NAME',
         help='The name of the resource')
-    arg.completer = resource_name_completer
+    arg.completer = resource_name_completer  # type: ignore[attr-defined]
 
     try:
         from argcomplete import autocomplete
diff --git a/ament_index_python/docs/source/conf.py b/ament_index_python/docs/source/conf.py
index ffcb7f9..052cc8a 100644
--- a/ament_index_python/docs/source/conf.py
+++ b/ament_index_python/docs/source/conf.py
@@ -30,6 +30,8 @@
 # import sys
 # sys.path.insert(0, os.path.abspath('.'))
 
+# -- Imports -----------------------------------------------------
+from typing import Dict, List, Sequence
 
 # -- Project information -----------------------------------------------------
 
@@ -82,7 +84,7 @@
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 # This pattern also affects html_static_path and html_extra_path.
-exclude_patterns = []
+exclude_patterns: Sequence[str] = []
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = None
@@ -104,7 +106,7 @@
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = []
+html_static_path: List[str] = []
 
 # Custom sidebar templates, must be a dictionary that maps document names
 # to template names.
@@ -125,7 +127,7 @@
 
 # -- Options for LaTeX output ------------------------------------------------
 
-latex_elements = {
+latex_elements: Dict[str, str] = {
     # The paper size ('letterpaper' or 'a4paper').
     #
     # 'papersize': 'letterpaper',
diff --git a/ament_index_python/package.xml b/ament_index_python/package.xml
index bc15f95..dc2646e 100644
--- a/ament_index_python/package.xml
+++ b/ament_index_python/package.xml
@@ -18,6 +18,7 @@
   <test_depend>ament_copyright</test_depend>
   <test_depend>ament_flake8</test_depend>
   <test_depend>ament_pep257</test_depend>
+  <test_depend>ament_mypy</test_depend>
   <test_depend>python3-pytest</test_depend>
 
   <export>
diff --git a/ament_index_python/py.typed b/ament_index_python/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/ament_index_python/test/test_mypy.py b/ament_index_python/test/test_mypy.py
new file mode 100644
index 0000000..16d0794
--- /dev/null
+++ b/ament_index_python/test/test_mypy.py
@@ -0,0 +1,20 @@
+# Copyright 2024 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from ament_mypy.main import main
+
+
+def test_mypy() -> None:
+    rc = main(argv=['--exclude', 'test'])
+    assert rc == 0, 'Found code style errors / warnings'