Perl script not recogonizing Telnet prompt -

i have perl script connects telnet server , runs basic commands on it. script using , works fine.

my $host =  '192.186.0.2'; print ("\nconnecting server ".$host);  $telnet->open($host); $telnet->waitfor('/login: $/i');  $telnet->print('admin');  $telnet->waitfor('/password: $/i');  $telnet->print('password');  $telnet->waitfor('/\$ $/i');  @output = $telnet->cmd('ls --color=none'); print ("@output\n"); 

but prompt on server looks this.

prompt> 

so modified code read.

$telnet->waitfor('/prompt> $/i');  

but pattern match timeout error. how can solve this?