diff --git a/dom/serviceworkers/ServiceWorkerRegistration.cpp b/dom/serviceworkers/ServiceWorkerRegistration.cpp
index c5886ee470a5..60b7810af1ac 100644
--- a/dom/serviceworkers/ServiceWorkerRegistration.cpp
+++ b/dom/serviceworkers/ServiceWorkerRegistration.cpp
@@ -334,11 +334,26 @@ already_AddRefed<Promise>
 ServiceWorkerRegistration::GetNotifications(const GetNotificationOptions& aOptions,
                                             ErrorResult& aRv)
 {
-  if (!mInner) {
+  nsIGlobalObject* global = GetParentObject();
+  if (!global) {
     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
     return nullptr;
   }
-  return mInner->GetNotifications(aOptions, aRv);
+
+  NS_ConvertUTF8toUTF16 scope(mDescriptor.Scope());
+
+  if (NS_IsMainThread()) {
+    nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(global);
+    if (NS_WARN_IF(!window)) {
+      aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+      return nullptr;
+    }
+    return Notification::Get(window, aOptions, scope, aRv);
+  }
+
+  WorkerPrivate* worker = GetCurrentThreadWorkerPrivate();
+  worker->AssertIsOnWorkerThread();
+  return Notification::WorkerGet(worker, aOptions, scope, aRv);
 }
 
 } // dom namespace
diff --git a/dom/serviceworkers/ServiceWorkerRegistration.h b/dom/serviceworkers/ServiceWorkerRegistration.h
index 150293f7c068..709c9e7013ab 100644
--- a/dom/serviceworkers/ServiceWorkerRegistration.h
+++ b/dom/serviceworkers/ServiceWorkerRegistration.h
@@ -49,10 +49,6 @@ public:
 
     virtual RefPtr<GenericPromise>
     Unregister() = 0;
-
-    virtual already_AddRefed<Promise>
-    GetNotifications(const GetNotificationOptions& aOptions,
-                     ErrorResult& aRv) = 0;
   };
 
   NS_DECLARE_STATIC_IID_ACCESSOR(NS_DOM_SERVICEWORKERREGISTRATION_IID)
diff --git a/dom/serviceworkers/ServiceWorkerRegistrationImpl.cpp b/dom/serviceworkers/ServiceWorkerRegistrationImpl.cpp
index c4f7f3c48e05..80778d6c971a 100644
--- a/dom/serviceworkers/ServiceWorkerRegistrationImpl.cpp
+++ b/dom/serviceworkers/ServiceWorkerRegistrationImpl.cpp
@@ -8,7 +8,6 @@
 
 #include "ipc/ErrorIPCUtils.h"
 #include "mozilla/dom/DOMPrefs.h"
-#include "mozilla/dom/Notification.h"
 #include "mozilla/dom/Promise.h"
 #include "mozilla/dom/PromiseWorkerProxy.h"
 #include "mozilla/dom/PushManagerBinding.h"
@@ -572,20 +571,6 @@ ServiceWorkerRegistrationMainThread::Unregister()
   return cb->Promise();
 }
 
-already_AddRefed<Promise>
-ServiceWorkerRegistrationMainThread::GetNotifications(const GetNotificationOptions& aOptions, ErrorResult& aRv)
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  MOZ_DIAGNOSTIC_ASSERT(mOuter);
-
-  nsCOMPtr<nsPIDOMWindowInner> window = mOuter->GetOwner();
-  if (NS_WARN_IF(!window)) {
-    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
-    return nullptr;
-  }
-  return Notification::Get(window, aOptions, mScope, aRv);
-}
-
 ////////////////////////////////////////////////////
 // Worker Thread implementation
 
@@ -955,14 +940,6 @@ WorkerListener::RegistrationRemoved()
   mRegistration->RegistrationRemoved();
 }
 
-already_AddRefed<Promise>
-ServiceWorkerRegistrationWorkerThread::GetNotifications(const GetNotificationOptions& aOptions,
-                                                        ErrorResult& aRv)
-{
-  MOZ_ASSERT(mWorkerRef && mWorkerRef->GetPrivate());
-  return Notification::WorkerGet(mWorkerRef->GetPrivate(), aOptions, mScope, aRv);
-}
-
 void
 ServiceWorkerRegistrationWorkerThread::UpdateFound()
 {
diff --git a/dom/serviceworkers/ServiceWorkerRegistrationImpl.h b/dom/serviceworkers/ServiceWorkerRegistrationImpl.h
index 2098ae988008..77d0c205f730 100644
--- a/dom/serviceworkers/ServiceWorkerRegistrationImpl.h
+++ b/dom/serviceworkers/ServiceWorkerRegistrationImpl.h
@@ -48,10 +48,6 @@ public:
   RefPtr<GenericPromise>
   Unregister() override;
 
-  already_AddRefed<Promise>
-  GetNotifications(const GetNotificationOptions& aOptions,
-                   ErrorResult& aRv) override;
-
   // ServiceWorkerRegistrationListener
   void
   UpdateFound() override;
@@ -119,10 +115,6 @@ public:
   RefPtr<GenericPromise>
   Unregister() override;
 
-  already_AddRefed<Promise>
-  GetNotifications(const GetNotificationOptions& aOptions,
-                   ErrorResult& aRv) override;
-
   void
   UpdateFound();