diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 6dee3b429a..e13c9e94c9 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2726,7 +2726,7 @@ pref("layout.css.resizeobserver.enabled", true);
 pref("layout.css.cascade-layers.enabled", true);
 
 // Is support for basic CSS nesting lowering enabled?
-pref("layout.css.nesting.enabled", false);
+pref("layout.css.nesting.enabled", true);
 
 // Should rules in imported style sheets be added based on the order
 // of appearance of their respective @import rules in the parent