diff --git a/include/wx/window.h b/include/wx/window.h
index 338073b554..6efb7a0249 100644
--- a/include/wx/window.h
+++ b/include/wx/window.h
@@ -1329,9 +1329,8 @@ protected:
     virtual void DoSetWindowVariant( wxWindowVariant variant ) ;
 
     // Must be called when mouse capture is lost to send
-    // wxMouseCaptureLostEvent to windows on capture stack. The argument is
-    // the window gaining capture or NULL if outside of wx code or none.
-    static void NotifyCaptureLost(wxWindow *gainedCapture);
+    // wxMouseCaptureLostEvent to windows on capture stack.
+    static void NotifyCaptureLost();
 
 private:
     // contains the last id generated by NewControlId
diff --git a/src/common/wincmn.cpp b/src/common/wincmn.cpp
index 101c995e7f..62995e54a8 100644
--- a/src/common/wincmn.cpp
+++ b/src/common/wincmn.cpp
@@ -2406,7 +2406,7 @@ static void DoNotifyWindowAboutCaptureLost(wxWindow *win)
 }
 
 /* static */
-void wxWindowBase::NotifyCaptureLost(wxWindow *gainedCapture)
+void wxWindowBase::NotifyCaptureLost()
 {
     // don't do anything if capture lost was expected, i.e. resulted from
     // a wx call to ReleaseMouse or CaptureMouse:
diff --git a/src/msw/window.cpp b/src/msw/window.cpp
index 2d079a5918..22b2626855 100644
--- a/src/msw/window.cpp
+++ b/src/msw/window.cpp
@@ -4107,12 +4107,11 @@ bool wxWindowMSW::HandlePaletteChanged(WXHWND hWndPalChange)
 
 bool wxWindowMSW::HandleCaptureChanged(WXHWND hWndGainedCapture)
 {
-    wxWindow *win = wxFindWinFromHandle(hWndGainedCapture);
-
     // notify windows on the capture stack about lost capture
     // (see http://sourceforge.net/tracker/index.php?func=detail&aid=1153662&group_id=9863&atid=109863):
-    wxWindowBase::NotifyCaptureLost(win);
+    wxWindowBase::NotifyCaptureLost();
 
+    wxWindow *win = wxFindWinFromHandle(hWndGainedCapture);
     wxMouseCaptureChangedEvent event(GetId(), win);
     event.SetEventObject(this);
     return GetEventHandler()->ProcessEvent(event);