diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
index ff1b8166cdc9..daf1fc3f281b 100644
--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -2473,7 +2473,7 @@
 
 - name: dom.arena_allocator.enabled
   type: bool
-  value: false
+  value: true
   mirror: once
 
 - name: dom.serviceWorkers.enabled