diff --git a/bos-settings/src/ui/sidebar.rs b/bos-settings/src/ui/sidebar.rs
index 70d3e09..bbc4fb1 100644
--- a/bos-settings/src/ui/sidebar.rs
+++ b/bos-settings/src/ui/sidebar.rs
@@ -55,7 +55,12 @@ pub const MAINTENANCE_ITEMS: &[SidebarItem] = &[
 
 pub const ABOUT_ITEMS: &[SidebarItem] = &[item("about", "About", "help-about-symbolic")];
 
-pub fn build() -> (GBox, ListBox) {
+/// `default_id` must match whatever page `window.rs` sets as the `Stack`'s
+/// initial visible child — previously these were two independent hardcoded
+/// "about" literals in different files with no link between them, so
+/// changing one without the other silently desynced the sidebar highlight
+/// from the actually-displayed page.
+pub fn build(default_id: &str) -> (GBox, ListBox) {
     let vbox = GBox::new(Orientation::Vertical, 0);
     vbox.add_css_class("sidebar");
     vbox.set_width_request(210);
@@ -69,12 +74,11 @@ pub fn build() -> (GBox, ListBox) {
     append_section(&list, "Maintenance", MAINTENANCE_ITEMS);
     append_section(&list, None, ABOUT_ITEMS);
 
-    // Select About so it matches the default stack page.
     let mut i = 0;
     loop {
         match list.row_at_index(i) {
             None => break,
-            Some(row) if row.widget_name() == "about" => {
+            Some(row) if row.widget_name() == default_id => {
                 list.select_row(Some(&row));
                 break;
             }
diff --git a/bos-settings/src/ui/window.rs b/bos-settings/src/ui/window.rs
index c74063e..67d62e0 100644
--- a/bos-settings/src/ui/window.rs
+++ b/bos-settings/src/ui/window.rs
@@ -4,6 +4,12 @@ use gtk4::{Application, ApplicationWindow, Orientation, Paned, Stack};
 use super::sidebar;
 use super::views;
 
+// About is a settings app's most GNOME-Settings-like landing page —
+// identifies the machine, no config editor thrown at you first. Defined
+// once here and threaded through to both the `Stack` and the sidebar's
+// initial selection, so the two can't independently drift out of sync.
+const DEFAULT_PAGE: &str = "about";
+
 pub fn build_ui(app: &Application) {
     let window = ApplicationWindow::builder()
         .application(app)
@@ -19,7 +25,7 @@ pub fn build_ui(app: &Application) {
     hpaned.set_shrink_start_child(false);
     hpaned.set_resize_start_child(false);
 
-    let (sidebar_box, list) = sidebar::build();
+    let (sidebar_box, list) = sidebar::build(DEFAULT_PAGE);
 
     let stack = Stack::new();
     stack.set_hexpand(true);
@@ -41,9 +47,7 @@ pub fn build_ui(app: &Application) {
     stack.add_named(&views::breadsearch::build(), Some("breadsearch"));
     stack.add_named(&views::hyprland::build(), Some("hyprland"));
 
-    // Default to About — a settings app's most GNOME-Settings-like landing
-    // page: identifies the machine, no config editor thrown at you first.
-    stack.set_visible_child_name("about");
+    stack.set_visible_child_name(DEFAULT_PAGE);
 
     {
         let stack = stack.clone();