diff --git a/dom/interfaces/base/nsIServiceWorkerManager.idl b/dom/interfaces/base/nsIServiceWorkerManager.idl
index 99f699b10a73..e7ab1bc3c48f 100644
--- a/dom/interfaces/base/nsIServiceWorkerManager.idl
+++ b/dom/interfaces/base/nsIServiceWorkerManager.idl
@@ -8,7 +8,7 @@
 interface nsIDocument;
 interface nsIURI;
 
-[uuid(8d2f64db-5585-4876-a1c9-391e16549068)]
+[builtinclass, uuid(79ad5b57-d65d-46d3-b5e9-32d27e16052d)]
 interface nsIServiceWorkerManager : nsISupports
 {
   /**