diff --git a/src/app/smoke-tests/thread/[threadId]/page.tsx b/src/app/smoke-tests/thread/[threadId]/page.tsx
index 5211d54..de7be1e 100644
--- a/src/app/smoke-tests/thread/[threadId]/page.tsx
+++ b/src/app/smoke-tests/thread/[threadId]/page.tsx
@@ -1,4 +1,5 @@
 import { notFound } from "next/navigation";
+import LiveUnreadCountBadge from "@/components/LiveUnreadCountBadge";
 
 interface Props {
   params: Promise<{ threadId: string }>;
@@ -12,10 +13,17 @@ export default async function SmokeThreadPage({ params }: Props) {
   const { threadId } = await params;
 
   return (
-    <div className="flex h-full items-center justify-center p-6">
+    <div className="flex h-full flex-col items-center justify-center gap-3 p-6">
       <h1 className="text-base font-semibold text-stone-900 dark:text-stone-100">
         Opened conversation {threadId}
       </h1>
+      <div
+        data-testid="shared-unread-count"
+        className="flex items-center gap-2 text-sm text-stone-500 dark:text-stone-400"
+      >
+        Shared unread count
+        <LiveUnreadCountBadge showZero />
+      </div>
     </div>
   );
 }
diff --git a/src/components/BrowserTabIndicator.tsx b/src/components/BrowserTabIndicator.tsx
index b8e372e..483d1c5 100644
--- a/src/components/BrowserTabIndicator.tsx
+++ b/src/components/BrowserTabIndicator.tsx
@@ -1,5 +1,6 @@
 "use client";
 
+import { usePathname } from "next/navigation";
 import { useEffect, useRef } from "react";
 import { useUnreadCount } from "@/components/UnreadCountProvider";
 import {
@@ -12,45 +13,49 @@ import {
 const MANAGED_FAVICON_SELECTOR = 'link[data-mail-unread-favicon="true"]';
 
 export default function BrowserTabIndicator() {
+  const pathname = usePathname();
   const unreadCount = useUnreadCount();
   const faviconRef = useRef<HTMLLinkElement | null>(null);
 
   useEffect(() => {
-    let favicon = document.head.querySelector<HTMLLinkElement>(
-      MANAGED_FAVICON_SELECTOR,
-    );
-    const createdFavicon = !favicon;
-
-    if (!favicon) {
-      favicon = document.createElement("link");
-      favicon.rel = "icon";
-      favicon.type = "image/svg+xml";
-      favicon.sizes = "any";
-      favicon.dataset.mailUnreadFavicon = "true";
-      document.head.append(favicon);
-    }
-
-    faviconRef.current = favicon;
-
     return () => {
       faviconRef.current = null;
-      if (createdFavicon) favicon.remove();
+      document.head
+        .querySelectorAll(MANAGED_FAVICON_SELECTOR)
+        .forEach((favicon) => favicon.remove());
     };
   }, []);
 
   useEffect(() => {
     const unreadLabel = formatBrowserTabUnreadCount(unreadCount);
-    const favicon = faviconRef.current;
+    const connectedFavicon = faviconRef.current?.isConnected
+      ? faviconRef.current
+      : document.head.querySelector<HTMLLinkElement>(
+          MANAGED_FAVICON_SELECTOR,
+        );
+    const favicon = connectedFavicon ?? document.createElement("link");
+
+    if (!connectedFavicon) {
+      favicon.setAttribute("rel", "icon");
+      favicon.setAttribute("type", "image/svg+xml");
+      favicon.setAttribute("sizes", "any");
+      favicon.setAttribute("data-mail-unread-favicon", "true");
+    }
 
     document.title = getBrowserTabTitle(unreadCount);
-
-    if (favicon) {
-      favicon.href = unreadLabel
+    favicon.setAttribute(
+      "href",
+      unreadLabel
         ? getUnreadFaviconDataUrl(unreadCount)
-        : DEFAULT_FAVICON_HREF;
-      favicon.dataset.unreadCount = unreadLabel;
-    }
-  }, [unreadCount]);
+        : DEFAULT_FAVICON_HREF,
+    );
+    favicon.setAttribute("data-unread-count", unreadLabel);
+    faviconRef.current = favicon;
+
+    // Next may rewrite static metadata while navigating. Keep this managed
+    // icon last so the browser continues to prefer the live unread state.
+    document.head.append(favicon);
+  }, [pathname, unreadCount]);
 
   return null;
 }
diff --git a/tests/smoke/mail.spec.ts b/tests/smoke/mail.spec.ts
index 3c550f6..1dadcea 100644
--- a/tests/smoke/mail.spec.ts
+++ b/tests/smoke/mail.spec.ts
@@ -41,6 +41,23 @@ test("keeps the browser tab in sync with live unread mail", async ({
   await expect(page).toHaveTitle("Mail");
   await expect(favicon).toHaveAttribute("href", /\/icon\.svg$/);
   await expect(favicon).toHaveAttribute("data-unread-count", "");
+
+  await page.getByRole("button", { name: "Set 99 unread" }).click();
+  await page.getByRole("link", { name: "Inbox" }).click();
+  await page
+    .locator('a[href="/smoke-tests/thread/thread-release"]')
+    .click();
+
+  await expect(page).toHaveURL("/smoke-tests/thread/thread-release");
+  await expect(page.getByTestId("shared-unread-count")).toContainText("99");
+  await expect(page).toHaveTitle("(99+) Mail");
+  await expect(favicon).toHaveAttribute("data-unread-count", "99+");
+  expect(
+    await page.evaluate(() => {
+      const icons = [...document.querySelectorAll('link[rel~="icon"]')];
+      return icons.at(-1)?.getAttribute("data-mail-unread-favicon");
+    }),
+  ).toBe("true");
 });
 
 test("loads sender artwork and falls back cleanly when it is unavailable", async ({