diff --git a/reactos/lib/user32/windows/nonclient.c b/reactos/lib/user32/windows/nonclient.c
index 0ae8dbeb018..e456da3264a 100644
--- a/reactos/lib/user32/windows/nonclient.c
+++ b/reactos/lib/user32/windows/nonclient.c
@@ -937,7 +937,6 @@ DefWndDoButton(HWND hWnd, WPARAM wParam)
       case WM_MOUSEMOVE:
         if(HasBtn)
         {
-          ClientToScreen(hWnd, &Msg.pt);
           CurBtn = DefWndNCHitTest(hWnd, Msg.pt);
           if(InBtn != (CurBtn == OrigBtn))
           {