diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 88c00a43b..d2596e138 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -122,6 +122,12 @@ repos:
         language: system
         types_or: [rst]
 
+    -   id: interrogate
+        name: interrogate
+        entry: interrogate src/ tests/ ci/
+        language: system
+        types_or: [python]
+
     -   id: pyproject-fmt-fix
         name: pyproject-fmt
         entry: pyproject-fmt
diff --git a/pyproject.toml b/pyproject.toml
index eed170f9f..8b6f0d8ec 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -58,6 +58,7 @@ optional-dependencies.dev = [
     "enum-tools[sphinx]==0.12.0",
     "freezegun==1.5.1",
     "furo==2024.5.6",
+    "interrogate==1.7.0",
     "mypy==1.10.0",
     "pre-commit==3.7.1",
     "pydocstyle==6.3",
@@ -352,6 +353,11 @@ plugins = [
 reportUnnecessaryTypeIgnoreComment = true
 typeCheckingMode = "strict"
 
+[tool.interrogate]
+fail-under = 100
+omit-covered-files = true
+verbose = 2
+
 [tool.pydantic-mypy]
 init_forbid_extra = true
 init_typed = true
diff --git a/src/mock_vws/_flask_server/__init__.py b/src/mock_vws/_flask_server/__init__.py
index e69de29bb..81533727f 100644
--- a/src/mock_vws/_flask_server/__init__.py
+++ b/src/mock_vws/_flask_server/__init__.py
@@ -0,0 +1 @@
+"""Flask server for the mock Vuforia web service."""
diff --git a/src/mock_vws/target.py b/src/mock_vws/target.py
index bdc47eac7..634088089 100644
--- a/src/mock_vws/target.py
+++ b/src/mock_vws/target.py
@@ -128,6 +128,7 @@ def status(self) -> str:
 
     @property
     def _post_processing_target_rating(self) -> int:
+        """The rating of the target after processing."""
         return self.target_tracking_rater(image_content=self.image_value)
 
     @property
diff --git a/tests/mock_vws/fixtures/credentials.py b/tests/mock_vws/fixtures/credentials.py
index 6ae04e43e..dfa5c86c6 100644
--- a/tests/mock_vws/fixtures/credentials.py
+++ b/tests/mock_vws/fixtures/credentials.py
@@ -27,6 +27,8 @@ class _VuforiaDatabaseSettings(BaseSettings):
 
 
 class _InactiveVuforiaDatabaseSettings(_VuforiaDatabaseSettings):
+    """Settings for an inactive Vuforia database."""
+
     model_config = SettingsConfigDict(
         env_prefix="INACTIVE_VUFORIA_",
         env_file=Path("vuforia_secrets.env"),
diff --git a/tests/mock_vws/fixtures/vuforia_backends.py b/tests/mock_vws/fixtures/vuforia_backends.py
index 8cf33efdb..2fbdf51f8 100644
--- a/tests/mock_vws/fixtures/vuforia_backends.py
+++ b/tests/mock_vws/fixtures/vuforia_backends.py
@@ -70,6 +70,7 @@ def _enable_use_real_vuforia(
     inactive_database: VuforiaDatabase,
     monkeypatch: pytest.MonkeyPatch,
 ) -> Generator[None, None, None]:
+    """Test against the real Vuforia."""
     assert monkeypatch
     assert inactive_database
     _delete_all_targets(database_keys=working_database)
@@ -81,6 +82,7 @@ def _enable_use_mock_vuforia(
     inactive_database: VuforiaDatabase,
     monkeypatch: pytest.MonkeyPatch,
 ) -> Generator[None, None, None]:
+    """Test against the in-memory mock Vuforia."""
     assert monkeypatch
     working_database = VuforiaDatabase(
         database_name=working_database.database_name,
@@ -110,6 +112,7 @@ def _enable_use_docker_in_memory(
     inactive_database: VuforiaDatabase,
     monkeypatch: pytest.MonkeyPatch,
 ) -> Generator[None, None, None]:
+    """Test against mock Vuforia created to be run in a container."""
     # We set ``wsgi.input_terminated`` to ``True`` so that when going through
     # ``requests`` in our tests, the Flask applications
     # have the given ``Content-Length`` headers and the given data in
diff --git a/tests/mock_vws/test_requests_mock_usage.py b/tests/mock_vws/test_requests_mock_usage.py
index ad3767ae5..55e08ad01 100644
--- a/tests/mock_vws/test_requests_mock_usage.py
+++ b/tests/mock_vws/test_requests_mock_usage.py
@@ -32,6 +32,7 @@ def _not_exact_matcher(
     first_image_content: bytes,
     second_image_content: bytes,
 ) -> bool:
+    """A matcher which returns True if the images are not the same."""
     return first_image_content != second_image_content