diff --git a/win32ss/user/user32/windows/window.c b/win32ss/user/user32/windows/window.c
index 048673ff106..bb42e4de4af 100644
--- a/win32ss/user/user32/windows/window.c
+++ b/win32ss/user/user32/windows/window.c
@@ -127,9 +127,9 @@ ChildWindowFromPointEx(HWND hwndParent,
 BOOL WINAPI
 CloseWindow(HWND hWnd)
 {
-    SendMessageA(hWnd, WM_SYSCOMMAND, SC_CLOSE, 0);
+    PostMessageW(hWnd, WM_SYSCOMMAND, SC_MINIMIZE, 0);
 
-    return HandleToUlong(hWnd);
+    return ValidateHwnd(hWndParent) != NULL;
 }
 
 FORCEINLINE