diff --git a/reactos/subsystems/win32/win32k/ntuser/winpos.c b/reactos/subsystems/win32/win32k/ntuser/winpos.c
index ba19166ed19..cca1c449b5e 100644
--- a/reactos/subsystems/win32/win32k/ntuser/winpos.c
+++ b/reactos/subsystems/win32/win32k/ntuser/winpos.c
@@ -895,6 +895,8 @@ co_WinPosSetWindowPos(
 
    ASSERT_REFS_CO(Window);
 
+   if (!Window->Wnd) return FALSE;
+
    /* FIXME: Get current active window from active queue. */
 
    /*