diff --git a/4.1-Extensions.md b/4.1-Extensions.md
index 93f1487..56d7c93 100644
--- a/4.1-Extensions.md
+++ b/4.1-Extensions.md
@@ -14,7 +14,7 @@ In no particular order...
 * [uBlock Origin](https://addons.mozilla.org/firefox/addon/ublock-origin/) <sup>✔ [Privacy](https://github.com/gorhill/uBlock/wiki/Privacy-policy)</sup> | [GitHub](https://github.com/gorhill/uBlock)
   * :exclamation: **CSP**: Uncheck `Dashboard > Settings > Block remote fonts`. Font **rules** use CSP [unsure about font filters]. Use Request Control instead.
 * [Privacy Badger](https://addons.mozilla.org/firefox/addon/privacy-badger17/) <sup>✔ [Privacy](https://addons.mozilla.org/firefox/addon/privacy-badger17/privacy/)</sup> | [GitHub](https://github.com/EFForg/privacybadger)
-   * Uses heuristics to learn and to build local blocking lists. Your mileage will depend on what other blocking extensions you use and their configurations, but it certainly can't hurt.
+   * Uses [heuristics](https://www.eff.org/privacybadger/faq#How-does-Privacy-Badger-work) to learn and to build local blocking lists. Your mileage will depend on what other blocking extensions you use and their configurations, but it [certainly can't hurt](https://www.eff.org/privacybadger/faq#Is-Privacy-Badger-compatible-with-other-extensions,-including-other-adblockers).
 * [uMatrix](https://addons.mozilla.org/firefox/addon/umatrix/) <sup>✔ [Privacy](https://github.com/gorhill/uMatrix/wiki/Privacy-policy)</sup> | [GitHub](https://github.com/gorhill/uMatrix)
   * :exclamation: **CSP**: uMatrix uses CSP for `$inline` and for web workers (maybe others)
 * [HTTPS Everywhere](https://addons.mozilla.org/firefox/addon/https-everywhere/) <sup>✔ [Privacy](https://www.eff.org/code/privacy/policy)</sup> | [GitHub](https://github.com/EFForg/https-everywhere)