diff --git a/antur/app.py b/antur/app.py
index f442a21..4223823 100644
--- a/antur/app.py
+++ b/antur/app.py
@@ -35,7 +35,7 @@ class AnturApp(App):
 
     SUB_TITLE = f"v{__version__}"
 
-    show_markdown = reactive(False)
+    show_markdown = reactive(default=False)
 
     def __init__(self: "AnturApp", url: str | None = None, *, max_concurrent_requests: int) -> None:
         """Initialize the Antur application."""
@@ -46,7 +46,7 @@ def __init__(self: "AnturApp", url: str | None = None, *, max_concurrent_request
 
     def compose(self: "AnturApp") -> ComposeResult:
         """Compose the layout of the app."""
-        yield Header(False)
+        yield Header(show_clock=False)
         yield SearchBar(self.url)
         with Vertical(id="contents"):
             with Vertical(id="main"):
diff --git a/antur/utils/__init__.py b/antur/utils/__init__.py
new file mode 100644
index 0000000..fbc0646
--- /dev/null
+++ b/antur/utils/__init__.py
@@ -0,0 +1 @@
+"""General utilities used through the application, such as sitemap parsing."""
diff --git a/antur/utils/sitemap_parser.py b/antur/utils/sitemap_parser.py
index bc92e09..4c8361d 100644
--- a/antur/utils/sitemap_parser.py
+++ b/antur/utils/sitemap_parser.py
@@ -4,7 +4,7 @@
 from dataclasses import dataclass
 
 import aiohttp
-from lxml.etree import Element, fromstring, tostring
+from lxml.etree import Element, XMLSyntaxError, fromstring, tostring
 
 from antur import __version__
 
@@ -29,7 +29,7 @@ class Error:
 
 
 HEADERS = {
-    "User-Agent": f"Mozilla/5.0 (compatible; AnturSitemap/{__version__}; +http://github.com/jb3/antur)"
+    "User-Agent": f"Mozilla/5.0 (compatible; AnturSitemap/{__version__}; +http://github.com/jb3/antur)",
 }
 
 IGNORE_TAGS = ["lastmod", "changefreq", "priority", "loc"]
@@ -51,9 +51,13 @@ def __init__(self: "SitemapParser", url: str, max_concurrent_requests: int) -> N
 
     async def get_data(self: "SitemapParser", url: str) -> bytes:
         """Fetch the data from the URL."""
-        async with aiohttp.ClientSession() as session, session.get(
-            url, headers=HEADERS
-        ) as response:
+        async with (
+            aiohttp.ClientSession() as session,
+            session.get(
+                url,
+                headers=HEADERS,
+            ) as response,
+        ):
             return await response.read()
 
     def _filter_out_children(self: "SitemapParser", element: Element) -> Element:
@@ -86,7 +90,7 @@ async def parse(self: "SitemapParser", url: str | None = None) -> dict[str, Entr
 
         try:
             parsed = fromstring(data)  # noqa: S320
-        except Exception as e:
+        except XMLSyntaxError as e:
             self.xml_errors += 1
             return Error(url, str(e))
 
@@ -100,8 +104,9 @@ async def parse(self: "SitemapParser", url: str | None = None) -> dict[str, Entr
 
             results = await asyncio.gather(*child_tasks.values())
 
-            for loc, result in zip(child_tasks.keys(), results):
-                level[loc] = result
+            level_data = dict(zip(child_tasks.keys(), results, strict=False))
+
+            level.update(level_data)
 
         if parsed.tag.endswith("urlset"):
             for child in parsed:
diff --git a/antur/widgets/__init__.py b/antur/widgets/__init__.py
new file mode 100644
index 0000000..c917d44
--- /dev/null
+++ b/antur/widgets/__init__.py
@@ -0,0 +1 @@
+"""Widgets used to display information through the application."""
diff --git a/antur/widgets/search_bar.py b/antur/widgets/search_bar.py
index d6aa6ba..bb81d8c 100644
--- a/antur/widgets/search_bar.py
+++ b/antur/widgets/search_bar.py
@@ -19,7 +19,7 @@ def is_url(value: str) -> bool:
             return False
 
         return all([result.scheme, result.netloc])
-    except Exception:
+    except ValueError:
         return False
 
 
diff --git a/antur/widgets/sitemap_tree.py b/antur/widgets/sitemap_tree.py
index 2ef455b..b579e17 100644
--- a/antur/widgets/sitemap_tree.py
+++ b/antur/widgets/sitemap_tree.py
@@ -28,7 +28,7 @@
 def dict_to_tree(dictionary: dict, tree: Tree | TreeNode) -> None:
     """Move a dictionary into the provided tree structure in-place."""
     for key, value in dictionary.items():
-        if isinstance(value, (Entry, Error)):
+        if isinstance(value, Entry | Error):
             tree.add_leaf(key, data=value)
         else:
             sub_tree = tree.add(key)
@@ -39,13 +39,17 @@ class CustomTree(Tree):
     """Custom tree widget to aid with formatting."""
 
     def render_label(
-        self: "CustomTree", node: TreeNode, base_style: Style, additional_style: Style
+        self: "CustomTree",
+        node: TreeNode,
+        base_style: Style,
+        additional_style: Style,
     ) -> Text:
         """Render the label with a custom style."""
         if hasattr(node, "data"):  # noqa: SIM102
             if isinstance(node.data, Error):
                 additional_style = Style.chain(
-                    additional_style, Style.from_color(Color.parse("red"))
+                    additional_style,
+                    Style.from_color(Color.parse("red")),
                 )
 
         return super().render_label(node, base_style, additional_style)