diff --git a/centreon-plugins/apps/protocols/x509/mode/certificate.pm b/centreon-plugins/apps/protocols/x509/mode/certificate.pm
index 734ce63c3..7ea8fcfa5 100644
--- a/centreon-plugins/apps/protocols/x509/mode/certificate.pm
+++ b/centreon-plugins/apps/protocols/x509/mode/certificate.pm
@@ -24,6 +24,7 @@ use base qw(centreon::plugins::templates::counter);
 
 use strict;
 use warnings;
+use Socket;
 use IO::Socket::SSL;
 use Net::SSLeay 1.42;
 use DateTime;