diff --git a/apps/pfsense/snmp/mode/runtime.pm b/apps/pfsense/snmp/mode/runtime.pm
index 84dce6160..2a765f737 100644
--- a/apps/pfsense/snmp/mode/runtime.pm
+++ b/apps/pfsense/snmp/mode/runtime.pm
@@ -25,6 +25,7 @@ use base qw(centreon::plugins::mode);
 use strict;
 use warnings;
 use centreon::plugins::misc;
+use POSIX;
 
 sub new {
     my ($class, %options) = @_;