diff --git a/docshell/base/nsDocShell.cpp b/docshell/base/nsDocShell.cpp
index 94d91d352e9c..899e3fb13aac 100644
--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -13964,3 +13964,36 @@ bool nsDocShell::IsSameDocumentAsActiveEntry(
     const mozilla::dom::SessionHistoryInfo& aSHInfo) {
   return mActiveEntry ? mActiveEntry->SharesDocumentWith(aSHInfo) : false;
 }
+
+// https://html.spec.whatwg.org/#nav-window
+nsPIDOMWindowInner* nsDocShell::GetActiveWindow() {
+  nsPIDOMWindowOuter* outer = GetWindow();
+  return outer ? outer->GetCurrentInnerWindow() : nullptr;
+}
+
+// https://html.spec.whatwg.org/#inform-the-navigation-api-about-aborting-navigation
+void nsDocShell::InformNavigationAPIAboutAbortingNavigation(JSContext* aCx) {
+  // Step 1
+  // This becomes an assert since we have a common event loop.
+  MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
+
+  // No ongoing navigations if we don't have a window.
+  RefPtr<nsPIDOMWindowInner> window = GetActiveWindow();
+  if (!window) {
+    return;
+  }
+
+  // Step 2
+  RefPtr<Navigation> navigation = window->Navigation();
+  if (!navigation) {
+    return;
+  }
+
+  // Step 3
+  if (!navigation->HasOngoingNavigateEvent()) {
+    return;
+  }
+
+  // Step 4
+  navigation->AbortOngoingNavigation(aCx);
+}
diff --git a/docshell/base/nsDocShell.h b/docshell/base/nsDocShell.h
index 771bdea2cfe0..347233a943d0 100644
--- a/docshell/base/nsDocShell.h
+++ b/docshell/base/nsDocShell.h
@@ -388,6 +388,8 @@ class nsDocShell final : public nsDocLoader,
     return mozilla::dom::WindowProxyHolder(mBrowsingContext);
   }
 
+  nsPIDOMWindowInner* GetActiveWindow();
+
   /**
    * Loads the given URI. See comments on nsDocShellLoadState members for more
    * information on information used.
@@ -1140,6 +1142,9 @@ class nsDocShell final : public nsDocLoader,
                       mozilla::dom::UserNavigationInvolvement::None);
 
  private:
+  MOZ_CAN_RUN_SCRIPT
+  void InformNavigationAPIAboutAbortingNavigation(JSContext* aCx);
+
   void SetCurrentURIInternal(nsIURI* aURI);
 
   // data members
diff --git a/dom/navigation/Navigation.cpp b/dom/navigation/Navigation.cpp
index 070bd8c891f9..b9493ac38742 100644
--- a/dom/navigation/Navigation.cpp
+++ b/dom/navigation/Navigation.cpp
@@ -1097,6 +1097,10 @@ void Navigation::SetFocusedChangedDuringOngoingNavigation(
   mFocusChangedDuringOngoingNavigation = aFocusChangedDUringOngoingNavigation;
 }
 
+bool Navigation::HasOngoingNavigateEvent() const {
+  return mOngoingNavigateEvent;
+}
+
 // The associated document of navigation's relevant global object.
 Document* Navigation::GetAssociatedDocument() const {
   nsGlobalWindowInner* window = GetOwnerWindow();
diff --git a/dom/navigation/Navigation.h b/dom/navigation/Navigation.h
index c0ba24528fb5..e8fb79192e6d 100644
--- a/dom/navigation/Navigation.h
+++ b/dom/navigation/Navigation.h
@@ -128,6 +128,11 @@ class Navigation final : public DOMEventTargetHelper {
   void SetFocusedChangedDuringOngoingNavigation(
       bool aFocusChangedDuringOngoingNavigation);
 
+  bool HasOngoingNavigateEvent() const;
+
+  void AbortOngoingNavigation(
+      JSContext* aCx, JS::Handle<JS::Value> aError = JS::UndefinedHandleValue);
+
  private:
   using UpcomingTraverseAPIMethodTrackers =
       nsTHashMap<nsIDHashKey, RefPtr<NavigationAPIMethodTracker>>;
@@ -183,9 +188,6 @@ class Navigation final : public DOMEventTargetHelper {
 
   static void CleanUp(NavigationAPIMethodTracker* aNavigationAPIMethodTracker);
 
-  void AbortOngoingNavigation(
-      JSContext* aCx, JS::Handle<JS::Value> aError = JS::UndefinedHandleValue);
-
   Document* GetAssociatedDocument() const;
 
   void LogHistory() const;