diff --git a/sphinx_external_toc/_compat.py b/sphinx_external_toc/_compat.py
index c87fb83..88275bc 100644
--- a/sphinx_external_toc/_compat.py
+++ b/sphinx_external_toc/_compat.py
@@ -1,4 +1,5 @@
 """Compatibility for using dataclasses instead of attrs."""
+
 from __future__ import annotations
 
 import dataclasses as dc
diff --git a/sphinx_external_toc/api.py b/sphinx_external_toc/api.py
index 3bd8155..eb742a6 100644
--- a/sphinx_external_toc/api.py
+++ b/sphinx_external_toc/api.py
@@ -1,4 +1,5 @@
 """Defines the `SiteMap` object, for storing the parsed ToC."""
+
 from collections.abc import MutableMapping
 from dataclasses import asdict, dataclass
 from typing import Any, Dict, Iterator, List, Optional, Set, Union
diff --git a/sphinx_external_toc/events.py b/sphinx_external_toc/events.py
index 8d468f4..9603b2b 100644
--- a/sphinx_external_toc/events.py
+++ b/sphinx_external_toc/events.py
@@ -1,4 +1,5 @@
 """Sphinx event functions and directives."""
+
 import glob
 from pathlib import Path, PurePosixPath
 from typing import Any, List, Optional, Set
diff --git a/sphinx_external_toc/parsing.py b/sphinx_external_toc/parsing.py
index 717b9fa..82b8046 100644
--- a/sphinx_external_toc/parsing.py
+++ b/sphinx_external_toc/parsing.py
@@ -1,4 +1,5 @@
 """Parse the ToC to a `SiteMap` object."""
+
 from collections.abc import Mapping
 from dataclasses import dataclass, fields
 from pathlib import Path