diff --git a/apps/desktop-shell/scripts/check-config.mjs b/apps/desktop-shell/scripts/check-config.mjs
index 07cc4e252..aec08b4a5 100644
--- a/apps/desktop-shell/scripts/check-config.mjs
+++ b/apps/desktop-shell/scripts/check-config.mjs
@@ -2446,14 +2446,23 @@ if (
 }
 for (const snippet of [
   'desktop_appearance_color_scheme',
+  'appearance_unavailable_response',
   'color_scheme_from_theme(theme)',
   'window.theme()',
   '"colorScheme"',
+  '"appearance unavailable"',
+  'appearance_unavailable_response_is_stable',
 ]) {
   if (!desktopHostBridgeAppearanceSource.includes(snippet)) {
     throw new Error(`desktop shell appearance module is missing ${snippet}`);
   }
 }
+if (
+  desktopHostBridgeAppearanceSource.includes('error.to_string()') ||
+  desktopHostBridgeAppearanceSource.includes('"main window not found"')
+) {
+  throw new Error('desktop shell appearance module must hide native window errors');
+}
 if (
   !desktopHostBridgeDispatchSource.includes(
     'set_desktop_app_badge_count(&app, &request)',
diff --git a/apps/desktop-shell/src-tauri/src/host_bridge/appearance.rs b/apps/desktop-shell/src-tauri/src/host_bridge/appearance.rs
index 134ae9dc3..d13f9228d 100644
--- a/apps/desktop-shell/src-tauri/src/host_bridge/appearance.rs
+++ b/apps/desktop-shell/src-tauri/src/host_bridge/appearance.rs
@@ -10,9 +10,9 @@ pub(crate) fn desktop_appearance_color_scheme(
     match app.get_webview_window("main") {
         Some(window) => match window.theme() {
             Ok(theme) => ok_color_scheme(request, color_scheme_from_theme(theme)),
-            Err(error) => failed(request.id.clone(), "host_error", error.to_string()),
+            Err(_) => appearance_unavailable_response(request),
         },
-        None => failed(request.id.clone(), "host_error", "main window not found"),
+        None => appearance_unavailable_response(request),
     }
 }
 
@@ -25,6 +25,10 @@ fn ok_color_scheme(request: &HostBridgeRequest, color_scheme: &'static str) -> H
     )
 }
 
+fn appearance_unavailable_response(request: &HostBridgeRequest) -> HostBridgeResponse {
+    failed(request.id.clone(), "host_error", "appearance unavailable")
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -42,4 +46,14 @@ mod tests {
             })
         );
     }
+
+    #[test]
+    fn appearance_unavailable_response_is_stable() {
+        let response = appearance_unavailable_response(&request("appearance.getColorScheme"));
+
+        assert!(!response.ok);
+        let error = response.error.expect("appearance error");
+        assert_eq!(error.code, "host_error");
+        assert_eq!(error.message, "appearance unavailable");
+    }
 }