diff --git a/files/en-us/mozilla/firefox/releases/133/index.md b/files/en-us/mozilla/firefox/releases/133/index.md
index 0ae40f3c612a50a..f54bea0ff571a40 100644
--- a/files/en-us/mozilla/firefox/releases/133/index.md
+++ b/files/en-us/mozilla/firefox/releases/133/index.md
@@ -38,6 +38,8 @@ This article provides information about the changes in Firefox 133 that affect d
 
 ### APIs
 
+- {{domxref("EventSource")}} is now supported in [service workers](/en-US/docs/Web/API/Service_Worker_API). ([Firefox bug 1681218](https://bugzil.la/1681218)).
+
 #### DOM
 
 #### Media, WebRTC, and Web Audio