diff --git a/Optional-Hardening.md b/Optional-Hardening.md
index 59e4ad0..98cb59c 100644
--- a/Optional-Hardening.md
+++ b/Optional-Hardening.md
@@ -5,9 +5,12 @@
       1) Go to *`☰ Settings` → Search → Default Search Engine*
       2) Change your default search engine to DuckDuckGo, or [add](https://github.com/yokoffing/Betterfox/blob/04c3184359c83d7b58411c3b68f40f3e9d95c373/Securefox.js#L600-L604) a premium search engine like [Kagi](https://kagi.com/).
 2) **Clear browsing data** on shutdown ([sanitize on close](https://github.com/yokoffing/Betterfox/blob/99f2e860633f307781ddb73d792358ad1bec6af5/Securefox.js#L409-L434)).
-   * You can **allow exceptions** if you want to stay logged in to some sites:
+    * You can **allow exceptions** if you want to stay logged in to some sites:
       1) Go to *`☰ Settings`→ Privacy & Security → Cookies and Site Data → Manage Exceptions*
       2) Check *Delete cookies and site data when Firefox is closed*.
+    * For cross-domain logins, add exceptions for both sites
+        * e.g. `https://www.youtube.com` (site) + `https://accounts.google.com` (single sign on)
+
 3) Apply preferences from the [common overrides](https://github.com/yokoffing/Betterfox/issues/87) sticky to enforce the following behavior:
    * Enable **HTTPS-Only Mode** outside of [Private Browsing](https://support.mozilla.org/en-US/kb/private-browsing-use-firefox-without-history) windows.
    * Block embedded **tweets, tiktoks, Instagram and Reddit posts** from loading on third-party sites.