diff --git a/widget/windows/WinIMEHandler.cpp b/widget/windows/WinIMEHandler.cpp
index 470a0c84627..fd62d1afd6c 100644
--- a/widget/windows/WinIMEHandler.cpp
+++ b/widget/windows/WinIMEHandler.cpp
@@ -198,6 +198,7 @@ IMEHandler::NotifyIME(nsWindow* aWindow,
     case REQUEST_TO_CANCEL_COMPOSITION:
       nsIMM32Handler::CancelComposition(aWindow);
       return NS_OK;
+    case NOTIFY_IME_OF_POSITION_CHANGE:
     case NOTIFY_IME_OF_COMPOSITION_UPDATE:
       nsIMM32Handler::OnUpdateComposition(aWindow);
       return NS_OK;
@@ -226,7 +227,7 @@ IMEHandler::GetUpdatePreference()
   }
 #endif //NS_ENABLE_TSF
 
-  return nsIMEUpdatePreference();
+  return nsIMM32Handler::GetIMEUpdatePreference();
 }
 
 // static
diff --git a/widget/windows/nsIMM32Handler.cpp b/widget/windows/nsIMM32Handler.cpp
index 275af68b426..0bb2dd78325 100644
--- a/widget/windows/nsIMM32Handler.cpp
+++ b/widget/windows/nsIMM32Handler.cpp
@@ -138,6 +138,13 @@ nsIMM32Handler::GetKeyboardCodePage()
   return sCodePage;
 }
 
+/* static */
+nsIMEUpdatePreference
+nsIMM32Handler::GetIMEUpdatePreference()
+{
+  return nsIMEUpdatePreference(nsIMEUpdatePreference::NOTIFY_POSITION_CHANGE);
+}
+
 // used for checking the lParam of WM_IME_COMPOSITION
 #define IS_COMPOSING_LPARAM(lParam) \
   ((lParam) & (GCS_COMPSTR | GCS_COMPATTR | GCS_COMPCLAUSE | GCS_CURSORPOS))
diff --git a/widget/windows/nsIMM32Handler.h b/widget/windows/nsIMM32Handler.h
index 107c2b1bfa6..656a1bdde4a 100644
--- a/widget/windows/nsIMM32Handler.h
+++ b/widget/windows/nsIMM32Handler.h
@@ -11,9 +11,9 @@
 #include "nsCOMPtr.h"
 #include "nsString.h"
 #include "nsTArray.h"
+#include "nsIWidget.h"
 #include "mozilla/EventForwards.h"
 
-class nsIWidget;
 class nsWindow;
 struct nsIntRect;
 
@@ -143,6 +143,8 @@ public:
   static void CancelComposition(nsWindow* aWindow, bool aForce = false);
   static void OnUpdateComposition(nsWindow* aWindow);
 
+  static nsIMEUpdatePreference GetIMEUpdatePreference();
+
 protected:
   static void EnsureHandlerInstance();