diff --git a/win32ss/user/ntuser/clipboard.c b/win32ss/user/ntuser/clipboard.c
index d144220a18..2ec385b1ce 100644
--- a/win32ss/user/ntuser/clipboard.c
+++ b/win32ss/user/ntuser/clipboard.c
@@ -375,6 +375,9 @@ UserClipboardRelease(PWND pWindow)
 {
     PWINSTATION_OBJECT pWinStaObj;
 
+    if (!pWindow) 
+        return;
+
     pWinStaObj = IntGetWinStaForCbAccess();
     if (!pWinStaObj)
         return;