diff --git a/src/bin/pg_ctl/t/001_start_stop.pl b/src/bin/pg_ctl/t/001_start_stop.pl
index a1143e34519..eb48a3fb83a 100644
--- a/src/bin/pg_ctl/t/001_start_stop.pl
+++ b/src/bin/pg_ctl/t/001_start_stop.pl
@@ -22,8 +22,10 @@ command_ok([ 'pg_ctl', 'initdb', '-D', "$tempdir/data", '-o', '-N' ],
 	'pg_ctl initdb');
 command_ok([ $ENV{PG_REGRESS}, '--config-auth', "$tempdir/data" ],
 	'configure authentication');
+my $node_port = get_free_port();
 open my $conf, '>>', "$tempdir/data/postgresql.conf";
 print $conf "fsync = off\n";
+print $conf "port = $node_port\n";
 print $conf TestLib::slurp_file($ENV{TEMP_CONFIG})
   if defined $ENV{TEMP_CONFIG};
 if (!$windows_os)