diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 864bfbd2cb..319a56fa2a 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -213,8 +213,7 @@ pref("dom.requestIdleCallback.enabled", true);
 
 // Enable Intersection Observers
 // See WD https://www.w3.org/TR/intersection-observer/
-// Disabled for now because of crashes. See #934 and #935
-pref("dom.IntersectionObserver.enabled", false);
+pref("dom.IntersectionObserver.enabled", true);
 
 // Whether the Gamepad API is enabled
 pref("dom.gamepad.enabled", true);