diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 6295b136c076..d9fc5f615495 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -3147,15 +3147,6 @@ nsGlobalWindow::SetNewDocument(nsIDocument* aDocument,
 
     if (currentInner && currentInner->GetWrapperPreserveColor()) {
       if (oldDoc == aDocument) {
-        // Move the navigator from the old inner window to the new one since
-        // this is a document.write. This is safe from a same-origin point of
-        // view because document.write can only be used by the same origin.
-        newInnerWindow->mNavigator = currentInner->mNavigator;
-        currentInner->mNavigator = nullptr;
-        if (newInnerWindow->mNavigator) {
-          newInnerWindow->mNavigator->SetWindow(newInnerWindow->AsInner());
-        }
-
         // Make a copy of the old window's performance object on document.open.
         // Note that we have to force eager creation of it here, because we need
         // to grab the current document channel and whatnot before that changes.
diff --git a/testing/web-platform/meta/html/dom/dynamic-markup-insertion/opening-the-input-stream/009.html.ini b/testing/web-platform/meta/html/dom/dynamic-markup-insertion/opening-the-input-stream/009.html.ini
index 23759ad03b67..3d78b55efd7b 100644
--- a/testing/web-platform/meta/html/dom/dynamic-markup-insertion/opening-the-input-stream/009.html.ini
+++ b/testing/web-platform/meta/html/dom/dynamic-markup-insertion/opening-the-input-stream/009.html.ini
@@ -1,8 +1,5 @@
 [009.html]
   type: testharness
-  [document.open replacing singleton navigator]
-    expected: FAIL
-
   [document.open replacing singleton sessionStorage]
     expected: FAIL