--- configure.ac.orig	2026-08-07 11:29:23.851720000 +0200
+++ configure.ac	2026-08-07 11:33:11.008191000 +0200
@@ -608,19 +608,9 @@
 AC_SUBST(test_gid)
 test_basedn=dc=example,dc=com
 AC_SUBST(test_basedn)
-while true ; do
-	test_ldapport=$RANDOM
-	if test $test_ldapport -ge 1024 ; then
-		break
-	fi
-done
+test_ldapport=`expr $$ % 64512 + 1024`
 AC_SUBST(test_ldapport)
-while true ; do
-	test_nisport=$RANDOM
-	if test $test_nisport -ge 1024 ; then
-		break
-	fi
-done
+test_nisport=`expr $$ % 63488 + 2048`
 if test "x$enable_nis" = xyes ; then
 AC_SUBST(test_nisport)
 NIS_PLUGIN_CONTINUE_WITHOUT_PORTMAP_ENV="nis_plugin_continue_without_portmap_for_testing_only_no_i_really_mean_that"