diff --git a/lib/Qpsmtpd/TcpServer.pm b/lib/Qpsmtpd/TcpServer.pm
index a2885b8..c270686 100644
--- a/lib/Qpsmtpd/TcpServer.pm
+++ b/lib/Qpsmtpd/TcpServer.pm
@@ -1,6 +1,7 @@
 package Qpsmtpd::TcpServer;
+use Qpsmtpd;
+@ISA = qw(Qpsmtpd);
 use strict;
-use base qw(Qpsmtpd);
 
 sub start_connection {
     my $self = shift;