diff --git a/scripts/shell.coffee b/scripts/shell.coffee
index 66f19a9..762ebae 100644
--- a/scripts/shell.coffee
+++ b/scripts/shell.coffee
@@ -18,7 +18,7 @@ isFromAdmin = (res) ->
   res.message.user.room is process.env.ADMIN_ROOM?.replace(':','#') or res.robot.adapterName is 'shell'
 
 runCmd = (cmd,res,cb) ->
-  res.send 'Operazione in corso: '+cmd
+  if res? then res.send 'Operazione in corso: '+cmd
   cp.exec cmd, (err,stdout,stderr) ->
     if res?
       if err