diff --git a/src/browser/callback_host.rs b/src/browser/callback_host.rs
index 6d18b0f..2dd8a5d 100644
--- a/src/browser/callback_host.rs
+++ b/src/browser/callback_host.rs
@@ -1162,6 +1162,38 @@ mod tests {
         );
     }
 
+    #[test]
+    fn live_callback_host_hidden_domain_sends_hide_open_page_command() {
+        let (ws_url, frames, handle) = start_fake_browser_status_server();
+
+        let result = LiveBrowserCallbackHost::start_with_browser_ws_url(
+            &ws_url,
+            "https://www.zhihu.com",
+            Duration::from_millis(100),
+            Duration::from_millis(50),
+            true,
+        );
+        assert!(result.is_err(), "expected timeout because no real helper page loads");
+        drop(result);
+        handle.join().unwrap();
+
+        let sent = frames.lock().unwrap().clone();
+        assert!(
+            sent.iter().any(|frame| frame.contains("sgHideBrowerserOpenPage")),
+            "hidden domain bootstrap should send sgHideBrowerserOpenPage; sent frames: {sent:?}"
+        );
+        assert!(
+            !sent.iter().any(|frame| {
+                frame.contains("\"sgBrowerserOpenPage\"")
+            }),
+            "hidden domain bootstrap should NOT send visible sgBrowerserOpenPage; sent frames: {sent:?}"
+        );
+        assert!(
+            sent.iter().any(|frame| frame.contains("/sgclaw/browser-helper.html")),
+            "bootstrap should include the helper page URL; sent frames: {sent:?}"
+        );
+    }
+
     #[test]
     fn live_callback_host_treats_simulated_mouse_command_as_fire_and_forget() {
         use crate::browser::callback_backend::{