--- a/dom/base/Console.cpp
+++ b/dom/base/Console.cpp
@@ -303,17 +303,17 @@ public:
   virtual bool Notify(JSContext* aCx, workers::Status aStatus) override
   {
     // We don't care about the notification. We just want to keep the
     // mWorkerPrivate alive.
     return true;
   }
 
 private:
-  NS_IMETHOD Run()
+  NS_IMETHOD Run() override
   {
     AssertIsOnMainThread();
 
     // Walk up to our containing page
     WorkerPrivate* wp = mWorkerPrivate;
     while (wp->GetParent()) {
       wp = wp->GetParent();
     }