diff --git a/ldap2dns.c b/ldap2dns.c
index 610534a..a92a639 100644
--- a/ldap2dns.c
+++ b/ldap2dns.c
@@ -805,7 +805,7 @@ static void calc_checksum(int* num, int* sum)
 	char* attr_list[2] = { "DNSserial", NULL };
 
 	*num = *sum = 0;
-	if ( ldaperr = ldap_search_ext_s(ldap_con, options.searchbase[0] ? options.searchbase : NULL, LDAP_SCOPE_SUBTREE, "objectclass=DNSzone", attr_list, 0, NULL, NULL, &options.searchtimeout, options.reclimit, &res)!=LDAP_SUCCESS )
+	if ( ldaperr = ldap_search_ext_s(ldap_con, options.searchbase[0] ? options.searchbase : NULL, LDAP_SCOPE_ONELEVEL, "objectclass=DNSzone", attr_list, 0, NULL, NULL, &options.searchtimeout, options.reclimit, &res)!=LDAP_SUCCESS )
 		die_ldap(ldaperr);
 	if (ldap_count_entries(ldap_con, res) < 1) {
 		fprintf(stderr, "[**] Warning: No records returned from search.  Check for correct credentials,\n[**] LDAP hostname, and search base DN.\n\n");