diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index 243af0a3ac66..7f6b6d204886 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -5097,6 +5097,12 @@ nsIDocument::DispatchContentLoadedEvents()
                                         true, true);
   }
 
+  nsPIDOMWindowInner* inner = GetInnerWindow();
+  if (inner) {
+    inner->NoteDOMContentLoaded();
+  }
+
+  // TODO
   if (mMaybeServiceWorkerControlled) {
     using mozilla::dom::ServiceWorkerManager;
     RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
diff --git a/dom/base/nsGlobalWindowInner.cpp b/dom/base/nsGlobalWindowInner.cpp
index 844cb6f7e3b6..4dd1bb2de309 100644
--- a/dom/base/nsGlobalWindowInner.cpp
+++ b/dom/base/nsGlobalWindowInner.cpp
@@ -2355,6 +2355,12 @@ nsPIDOMWindowInner::NoteCalledRegisterForServiceWorkerScope(const nsACString& aS
   nsGlobalWindowInner::Cast(this)->NoteCalledRegisterForServiceWorkerScope(aScope);
 }
 
+void
+nsPIDOMWindowInner::NoteDOMContentLoaded()
+{
+  nsGlobalWindowInner::Cast(this)->NoteDOMContentLoaded();
+}
+
 bool
 nsGlobalWindowInner::ShouldReportForServiceWorkerScope(const nsAString& aScope)
 {
@@ -2471,6 +2477,16 @@ nsGlobalWindowInner::NoteCalledRegisterForServiceWorkerScope(const nsACString& a
   mClientSource->NoteCalledRegisterForServiceWorkerScope(aScope);
 }
 
+void
+nsGlobalWindowInner::NoteDOMContentLoaded()
+{
+  if (!mClientSource) {
+    return;
+  }
+
+  mClientSource->NoteDOMContentLoaded();
+}
+
 void
 nsGlobalWindowInner::MigrateStateForDocumentOpen(nsGlobalWindowInner* aOldInner)
 {
diff --git a/dom/base/nsGlobalWindowInner.h b/dom/base/nsGlobalWindowInner.h
index 40341e342b0e..ae76d2f0fb3d 100644
--- a/dom/base/nsGlobalWindowInner.h
+++ b/dom/base/nsGlobalWindowInner.h
@@ -365,6 +365,8 @@ public:
 
   void NoteCalledRegisterForServiceWorkerScope(const nsACString& aScope);
 
+  void NoteDOMContentLoaded();
+
   virtual nsresult FireDelayedDOMEvents() override;
 
   virtual nsresult SetNewDocument(nsIDocument *aDocument,
diff --git a/dom/base/nsPIDOMWindow.h b/dom/base/nsPIDOMWindow.h
index 4bbf41d2933a..193859c05c62 100644
--- a/dom/base/nsPIDOMWindow.h
+++ b/dom/base/nsPIDOMWindow.h
@@ -332,6 +332,8 @@ public:
 
   void NoteCalledRegisterForServiceWorkerScope(const nsACString& aScope);
 
+  void NoteDOMContentLoaded();
+
   mozilla::dom::TabGroup* TabGroup();
 
   virtual nsPIDOMWindowOuter* GetPrivateRoot() = 0;
diff --git a/dom/clients/manager/ClientSource.cpp b/dom/clients/manager/ClientSource.cpp
index 13be3a8c2882..3bbc417b9136 100644
--- a/dom/clients/manager/ClientSource.cpp
+++ b/dom/clients/manager/ClientSource.cpp
@@ -477,6 +477,22 @@ ClientSource::GetController() const
   return mController;
 }
 
+void
+ClientSource::NoteDOMContentLoaded()
+{
+  if (mController.isSome() && !ServiceWorkerParentInterceptEnabled()) {
+    AssertIsOnMainThread();
+    RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
+    if (swm) {
+      swm->MaybeCheckNavigationUpdate(mClientInfo);
+    }
+  }
+
+  MaybeExecute([] (PClientSourceChild* aActor) {
+    aActor->SendNoteDOMContentLoaded();
+  });
+}
+
 RefPtr<ClientOpPromise>
 ClientSource::Focus(const ClientFocusArgs& aArgs)
 {
diff --git a/dom/clients/manager/ClientSource.h b/dom/clients/manager/ClientSource.h
index b67bcb6e8f3b..671f40ccae83 100644
--- a/dom/clients/manager/ClientSource.h
+++ b/dom/clients/manager/ClientSource.h
@@ -150,6 +150,11 @@ public:
   const Maybe<ServiceWorkerDescriptor>&
   GetController() const;
 
+  // Note that the client has reached DOMContentLoaded.  Only applies to window
+  // clients.
+  void
+  NoteDOMContentLoaded();
+
   RefPtr<ClientOpPromise>
   Focus(const ClientFocusArgs& aArgs);
 
diff --git a/dom/clients/manager/ClientSourceParent.cpp b/dom/clients/manager/ClientSourceParent.cpp
index 0b6b8736b3c3..a46f5ba49121 100644
--- a/dom/clients/manager/ClientSourceParent.cpp
+++ b/dom/clients/manager/ClientSourceParent.cpp
@@ -170,6 +170,24 @@ ClientSourceParent::RecvInheritController(const ClientControlledArgs& aArgs)
   return IPC_OK();
 }
 
+IPCResult
+ClientSourceParent::RecvNoteDOMContentLoaded()
+{
+  if (mController.isSome() && ServiceWorkerParentInterceptEnabled()) {
+    nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+      "ClientSourceParent::RecvNoteDOMContentLoaded",
+      [clientInfo = mClientInfo] () {
+        RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
+        NS_ENSURE_TRUE_VOID(swm);
+
+        swm->MaybeCheckNavigationUpdate(clientInfo);
+      });
+
+    MOZ_ALWAYS_SUCCEEDS(SystemGroup::Dispatch(TaskCategory::Other, r.forget()));
+  }
+  return IPC_OK();
+}
+
 void
 ClientSourceParent::ActorDestroy(ActorDestroyReason aReason)
 {
diff --git a/dom/clients/manager/ClientSourceParent.h b/dom/clients/manager/ClientSourceParent.h
index cce3734f394a..d618d5ee5cda 100644
--- a/dom/clients/manager/ClientSourceParent.h
+++ b/dom/clients/manager/ClientSourceParent.h
@@ -48,6 +48,9 @@ class ClientSourceParent final : public PClientSourceParent
   mozilla::ipc::IPCResult
   RecvInheritController(const ClientControlledArgs& aArgs) override;
 
+  mozilla::ipc::IPCResult
+  RecvNoteDOMContentLoaded() override;
+
   void
   ActorDestroy(ActorDestroyReason aReason) override;
 
diff --git a/dom/clients/manager/PClientSource.ipdl b/dom/clients/manager/PClientSource.ipdl
index 1229bc01dcd7..41d7cbad59ba 100644
--- a/dom/clients/manager/PClientSource.ipdl
+++ b/dom/clients/manager/PClientSource.ipdl
@@ -26,6 +26,7 @@ parent:
   async Freeze();
   async Thaw();
   async InheritController(ClientControlledArgs aArgs);
+  async NoteDOMContentLoaded();
 
 child:
   async PClientSourceOp(ClientOpConstructorArgs aArgs);