--- a/dom/workers/ServiceWorkerManager.cpp
+++ b/dom/workers/ServiceWorkerManager.cpp
@@ -1208,22 +1208,22 @@ ServiceWorkerManager::GetServiceWorkerRe
     return nullptr;
   }
 
   nsCString scope = FindScopeForPath(domainInfo->mOrderedScopes, spec);
   if (scope.IsEmpty()) {
     return nullptr;
   }
 
-  ServiceWorkerRegistration* registration;
-  domainInfo->mServiceWorkerRegistrations.Get(scope, &registration);
+  nsRefPtr<ServiceWorkerRegistration> registration;
+  domainInfo->mServiceWorkerRegistrations.Get(scope, getter_AddRefs(registration));
   // ordered scopes and registrations better be in sync.
   MOZ_ASSERT(registration);
 
-  return registration;
+  return registration.forget();
 }
 
 namespace {
 /*
  * Returns string without trailing '*'.
  */
 void ScopeWithoutStar(const nsACString& aScope, nsACString& out)
 {