--- a/widget/windows/nsBidiKeyboard.cpp
+++ b/widget/windows/nsBidiKeyboard.cpp
@@ -2,16 +2,20 @@
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include <stdio.h>
 #include "nsBidiKeyboard.h"
 #include "prmem.h"
+#include "nsServiceManagerUtils.h"
+#include "nsTArray.h"
+#include "nsContentUtils.h"
+#include "mozilla/dom/ContentParent.h"
 #include <tchar.h>
 
 NS_IMPL_ISUPPORTS(nsBidiKeyboard, nsIBidiKeyboard)
 
 nsBidiKeyboard::nsBidiKeyboard() : nsIBidiKeyboard()
 {
   Reset();
 }
@@ -172,8 +176,29 @@ bool nsBidiKeyboard::IsRTLLanguage(HKL a
 {
   LOCALESIGNATURE localesig;
   return (::GetLocaleInfoW(PRIMARYLANGID((DWORD_PTR)aLocale),
                            LOCALE_FONTSIGNATURE,
                            (LPWSTR)&localesig,
                            (sizeof(localesig)/sizeof(WCHAR))) &&
           (localesig.lsUsb[3] & 0x08000000));
 }
+
+//static
+void
+nsBidiKeyboard::OnLayoutChange()
+{
+  nsCOMPtr<nsIBidiKeyboard> bidiKeyboard = nsContentUtils::GetBidiKeyboard();
+  if (!bidiKeyboard) {
+    return;
+  }
+
+  bool rtl;
+  if (NS_FAILED(bidiKeyboard->IsLangRTL(&rtl))) {
+    return;
+  }
+
+  nsTArray<mozilla::dom::ContentParent*> children;
+  mozilla::dom::ContentParent::GetAll(children);
+  for (uint32_t i = 0; i < children.Length(); i++) {
+    children[i]->SendBidiKeyboardNotify(rtl);
+  }
+}

--- a/widget/windows/nsBidiKeyboard.h
+++ b/widget/windows/nsBidiKeyboard.h
@@ -14,16 +14,18 @@ class nsBidiKeyboard : public nsIBidiKey
   virtual ~nsBidiKeyboard();
 
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSIBIDIKEYBOARD
 
   nsBidiKeyboard();
 
+  static void OnLayoutChange();
+
 protected:
 
   nsresult SetupBidiKeyboards();
   bool IsRTLLanguage(HKL aLocale);
 
   bool mInitialized;
   bool mHaveBidiKeyboards;
   wchar_t  mLTRKeyboard[KL_NAMELENGTH];

--- a/widget/windows/nsWidgetFactory.cpp
+++ b/widget/windows/nsWidgetFactory.cpp
@@ -185,17 +185,17 @@ static const mozilla::Module::CIDEntry k
   { &kNS_WIN_TASKBAR_CID, false, nullptr, WinTaskbarConstructor },
   { &kNS_WIN_JUMPLISTBUILDER_CID, false, nullptr, JumpListBuilderConstructor },
   { &kNS_WIN_JUMPLISTITEM_CID, false, nullptr, JumpListItemConstructor },
   { &kNS_WIN_JUMPLISTSEPARATOR_CID, false, nullptr, JumpListSeparatorConstructor },
   { &kNS_WIN_JUMPLISTLINK_CID, false, nullptr, JumpListLinkConstructor },
   { &kNS_WIN_JUMPLISTSHORTCUT_CID, false, nullptr, JumpListShortcutConstructor },
   { &kNS_WINDOWS_UIUTILS_CID, false, nullptr, WindowsUIUtilsConstructor },
   { &kNS_DRAGSERVICE_CID, false, nullptr, nsDragServiceConstructor, Module::MAIN_PROCESS_ONLY },
-  { &kNS_BIDIKEYBOARD_CID, false, nullptr, nsBidiKeyboardConstructor },
+  { &kNS_BIDIKEYBOARD_CID, false, nullptr, nsBidiKeyboardConstructor, Module::MAIN_PROCESS_ONLY },
   { &kNS_TASKBARPREVIEWCALLBACK_CID, false, nullptr, TaskbarPreviewCallbackConstructor },
 #ifdef NS_PRINTING
   { &kNS_PRINTSETTINGSSERVICE_CID, false, nullptr, nsPrintOptionsWinConstructor },
   { &kNS_PRINTER_ENUMERATOR_CID, false, nullptr, nsPrinterEnumeratorWinConstructor },
   { &kNS_PRINTSESSION_CID, false, nullptr, nsPrintSessionConstructor },
   { &kNS_DEVICE_CONTEXT_SPEC_CID, false, nullptr, nsDeviceContextSpecWinConstructor },
 #endif
   { nullptr }
@@ -219,17 +219,17 @@ static const mozilla::Module::ContractID
   { "@mozilla.org/windows-taskbar;1", &kNS_WIN_TASKBAR_CID },
   { "@mozilla.org/windows-jumplistbuilder;1", &kNS_WIN_JUMPLISTBUILDER_CID },
   { "@mozilla.org/windows-jumplistitem;1", &kNS_WIN_JUMPLISTITEM_CID },
   { "@mozilla.org/windows-jumplistseparator;1", &kNS_WIN_JUMPLISTSEPARATOR_CID },
   { "@mozilla.org/windows-jumplistlink;1", &kNS_WIN_JUMPLISTLINK_CID },
   { "@mozilla.org/windows-jumplistshortcut;1", &kNS_WIN_JUMPLISTSHORTCUT_CID },
   { "@mozilla.org/windows-ui-utils;1", &kNS_WINDOWS_UIUTILS_CID },
   { "@mozilla.org/widget/dragservice;1", &kNS_DRAGSERVICE_CID, Module::MAIN_PROCESS_ONLY },
-  { "@mozilla.org/widget/bidikeyboard;1", &kNS_BIDIKEYBOARD_CID },
+  { "@mozilla.org/widget/bidikeyboard;1", &kNS_BIDIKEYBOARD_CID, Module::MAIN_PROCESS_ONLY },
   { "@mozilla.org/widget/taskbar-preview-callback;1", &kNS_TASKBARPREVIEWCALLBACK_CID },
 #ifdef NS_PRINTING
   { "@mozilla.org/gfx/printsettings-service;1", &kNS_PRINTSETTINGSSERVICE_CID },
   { "@mozilla.org/gfx/printerenumerator;1", &kNS_PRINTER_ENUMERATOR_CID },
   { "@mozilla.org/gfx/printsession;1", &kNS_PRINTSESSION_CID },
   { "@mozilla.org/gfx/devicecontextspec;1", &kNS_DEVICE_CONTEXT_SPEC_CID },
 #endif
   { nullptr }

--- a/widget/windows/nsWindow.cpp
+++ b/widget/windows/nsWindow.cpp
@@ -128,16 +128,17 @@
 #include "nsIWidgetListener.h"
 #include "mozilla/dom/Touch.h"
 #include "mozilla/gfx/2D.h"
 #include "nsToolkitCompsCID.h"
 #include "nsIAppStartup.h"
 #include "mozilla/WindowsVersion.h"
 #include "mozilla/TextEvents.h" // For WidgetKeyboardEvent
 #include "nsThemeConstants.h"
+#include "nsBidiKeyboard.h"
 
 #include "nsIGfxInfo.h"
 #include "nsUXThemeConstants.h"
 #include "KeyboardLayout.h"
 #include "nsNativeDragTarget.h"
 #include <mmsystem.h> // needed for WIN32_LEAN_AND_MEAN
 #include <zmouse.h>
 #include <richedit.h>
@@ -5510,16 +5511,17 @@ nsWindow::ProcessMessage(UINT msg, WPARA
     case WM_INPUTLANGCHANGEREQUEST:
       *aRetValue = TRUE;
       result = false;
       break;
 
     case WM_INPUTLANGCHANGE:
       KeyboardLayout::GetInstance()->
         OnLayoutChange(reinterpret_cast<HKL>(lParam));
+      nsBidiKeyboard::OnLayoutChange();
       result = false; // always pass to child window
       break;
 
     case WM_DESTROYCLIPBOARD:
     {
       nsIClipboard* clipboard;
       nsresult rv = CallGetService(kCClipboardCID, &clipboard);
       if(NS_SUCCEEDED(rv)) {