diff --git a/Appendix-B:-Firefox-Add-ons.md b/Appendix-B:-Firefox-Add-ons.md
index 2d57083..dbf83c5 100644
--- a/Appendix-B:-Firefox-Add-ons.md
+++ b/Appendix-B:-Firefox-Add-ons.md
@@ -20,6 +20,7 @@ These are all, where applicable, best configured to `deny-all` and whitelist.
 * [Self-Destructing Cookies](https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies/) <sup>1</sup>
 * [Smart Referer](https://addons.mozilla.org/en-US/firefox/addon/smart-referer/) :pushpin:
   * Will be disabled by FF53 (`multiprocessCompatible` flag is missing)
+  * [WebExtension](https://github.com/meh/smart-referer/tree/wext) under development
 * [HTTPS Everywhere](https://addons.mozilla.org/en-US/firefox/addon/https-everywhere/)
 * [CanvasBlocker](https://addons.mozilla.org/en-US/firefox/addon/canvasblocker/)
 * [No Resource URI Leak](https://addons.mozilla.org/en-US/firefox/addon/no-resource-uri-leak/)