--- a/check_libs/nagios-check-libs
+++ b/check_libs/nagios-check-libs
@@ -29,7 +29,7 @@ use Getopt::Long;
 $ENV{'PATH'} = '/bin:/sbin:/usr/bin:/usr/sbin';
 delete @ENV{'IFS', 'CDPATH', 'ENV', 'BASH_ENV'};
 
-my $LSOF = '/usr/bin/lsof -F0';
+my $LSOF = '/usr/bin/lsof -nPF0';
 my $VERSION = '0.2012042101';
 
 # nagios exit codes
