diff --git a/tests/test_updater.py b/tests/test_updater.py
index cf8c657..5813258 100644
--- a/tests/test_updater.py
+++ b/tests/test_updater.py
@@ -215,9 +215,7 @@ def test_refresh_caddyfile_substitutes_hostname_placeholder(updater, tmp_path):
     # this the named-hostname :443 block ships with a literal
     # `__FURTKA_HOSTNAME__` and Caddy refuses to load the config.
     src = tmp_path / "src"
-    src.write_text(
-        "__FURTKA_HOSTNAME__.local, __FURTKA_HOSTNAME__ {\n\ttls internal\n}\n"
-    )
+    src.write_text("__FURTKA_HOSTNAME__.local, __FURTKA_HOSTNAME__ {\n\ttls internal\n}\n")
     assert updater._refresh_caddyfile(src) is True
     live = updater._CADDYFILE_LIVE.read_text()
     assert "testbox.local, testbox {" in live
diff --git a/tests/test_webinstaller_assets.py b/tests/test_webinstaller_assets.py
index 5b82249..b4b022e 100644
--- a/tests/test_webinstaller_assets.py
+++ b/tests/test_webinstaller_assets.py
@@ -172,9 +172,7 @@ def test_post_install_substitutes_hostname_in_caddyfile(install_cmds):
     # with the hostname the user picked in the form. The `testhost` value
     # comes from the install_cmds fixture. Without substitution Caddy's
     # `tls internal` never issues a leaf cert for the real hostname.
-    caddyfile_cmd = next(
-        (c for c in install_cmds if " > /etc/caddy/Caddyfile" in c), None
-    )
+    caddyfile_cmd = next((c for c in install_cmds if " > /etc/caddy/Caddyfile" in c), None)
     assert caddyfile_cmd is not None
     written = _extract_written_content(caddyfile_cmd, "/etc/caddy/Caddyfile")
     assert "__FURTKA_HOSTNAME__" not in written
diff --git a/webinstaller/app.py b/webinstaller/app.py
index be4cafe..0392192 100644
--- a/webinstaller/app.py
+++ b/webinstaller/app.py
@@ -49,6 +49,7 @@ FURTKA_VERSION = _resolve_version()
 def _inject_version():
     return {"furtka_version": FURTKA_VERSION}
 
+
 LANGUAGES = {
     "en": {"locale": "en_US.UTF-8", "label": "English", "keyboard": "us"},
     "de": {"locale": "de_DE.UTF-8", "label": "Deutsch", "keyboard": "de"},