diff --git a/servers/slapd/back-bdb/attr.c b/servers/slapd/back-bdb/attr.c
index 0ccbc0e862..2419a343bb 100644
--- a/servers/slapd/back-bdb/attr.c
+++ b/servers/slapd/back-bdb/attr.c
@@ -215,7 +215,7 @@ bdb_attr_index_config(
 			goto done;
 		}
 
-		if( slap_ad_is_binary( ad ) ) {
+		if( ad == slap_schema.si_ad_entryDN || slap_ad_is_binary( ad ) ) {
 			if (c_reply) {
 				snprintf(c_reply->msg, sizeof(c_reply->msg),
 					"index of attribute \"%s\" disallowed", attrs[i] );