--- a/widget/windows/WinIMEHandler.cpp
+++ b/widget/windows/WinIMEHandler.cpp
@@ -498,16 +498,32 @@ IMEHandler::AssociateIMEContext(nsWindow
   }
   context.Disassociate();
 }
 
 // static
 void
 IMEHandler::InitInputContext(nsWindow* aWindow, InputContext& aInputContext)
 {
+  MOZ_ASSERT(aWindow);
+  MOZ_ASSERT(aWindow->GetWindowHandle(),
+             "IMEHandler::SetInputContext() requires non-nullptr HWND");
+
+  static bool sInitialized = false;
+  if (!sInitialized) {
+    sInitialized = true;
+    // Some TIPs like QQ Input (Simplified Chinese) may need normal window
+    // (i.e., windows except message window) when initializing themselves.
+    // Therefore, we need to initialize TSF/IMM modules after first normal
+    // window is created.  InitInputContext() should be called immediately
+    // after creating each normal window, so, here is a good place to
+    // initialize these modules.
+    Initialize();
+  }
+
   // For a11y, the default enabled state should be 'enabled'.
   aInputContext.mIMEState.mEnabled = IMEState::ENABLED;
 
 #ifdef NS_ENABLE_TSF
   if (sIsInTSFMode) {
     TSFTextStore::SetInputContext(aWindow, aInputContext,
       InputContextAction(InputContextAction::CAUSE_UNKNOWN,
                          InputContextAction::WIDGET_CREATED));

--- a/widget/windows/WinIMEHandler.h
+++ b/widget/windows/WinIMEHandler.h
@@ -25,18 +25,26 @@ struct MSGResult;
 /**
  * IMEHandler class is a mediator class.  On Windows, there are two IME API
  * sets: One is IMM which is legacy API set. The other is TSF which is modern
  * API set. By using this class, non-IME handler classes don't need to worry
  * that we're in which mode.
  */
 class IMEHandler final
 {
+private:
+  /**
+   * Initialize() initializes both TSF modules and IMM modules.  Some TIPs
+   * may require a normal window (i.e., not message window) belonging to
+   * this process.  Therefore, this is called immediately after first normal
+   * window is created.
+   */
+  static void Initialize();
+
 public:
-  static void Initialize();
   static void Terminate();
 
   /**
    * Returns TSF related native data or native IME context.
    */
   static void* GetNativeData(nsWindow* aWindow, uint32_t aDataType);
 
   /**

--- a/widget/windows/nsWindow.cpp
+++ b/widget/windows/nsWindow.cpp
@@ -650,17 +650,16 @@ nsWindow::nsWindow(bool aIsChildWindow)
   if (!sInstanceCount) {
     // Global app registration id for Win7 and up. See
     // WinTaskbar.cpp for details.
     mozilla::widget::WinTaskbar::RegisterAppUserModelID();
     KeyboardLayout::GetInstance()->OnLayoutChange(::GetKeyboardLayout(0));
 #if defined(ACCESSIBILITY)
     mozilla::TIPMessageHandler::Initialize();
 #endif // defined(ACCESSIBILITY)
-    IMEHandler::Initialize();
     if (SUCCEEDED(::OleInitialize(nullptr))) {
       sIsOleInitialized = TRUE;
     }
     NS_ASSERTION(sIsOleInitialized, "***** OLE is not initialized!\n");
     MouseScrollHandler::Initialize();
     // Init theme data
     nsUXThemeData::UpdateNativeThemeInfo();
     RedirectedKeyDownMessageManager::Forget();