diff --git a/CHANGES b/CHANGES
index 971b8950e7d1f1f94b9aa2b2d3f1bfd10359a814..02fa6045d2e116ee5587629320f415530d94ba78 100644
--- a/CHANGES
+++ b/CHANGES
@@ -6,6 +6,7 @@ OpenLDAP 2.4.12 Engineering
 	Fixed slapd aci performance (ITS#5636)
 	Fixed slapd aci's with sets (ITS#5627)
 	Fixed slapd attribute leak (ITS#5683)
+	Fixed slapd config backend with index greater than sibs (ITS#5684)
 	Fixed slapd custom attribute inheritance (ITS#5642)
 	Fixed slapd dynacl mask handling (ITS#5637)
 	Fixed slapd firstComponentMatch normalization (ITS#5634)
diff --git a/servers/slapd/bconfig.c b/servers/slapd/bconfig.c
index a27299e4e82a92a5335cf515693b0084f7bf50ae..fe8347478e36cdcc80de73ca342437c3f6adb5e9 100644
--- a/servers/slapd/bconfig.c
+++ b/servers/slapd/bconfig.c
@@ -3881,7 +3881,7 @@ check_name_index( CfEntryInfo *parent, ConfigType ce_type, Entry *e,
 		if ( isconfig && index == -1 ) {
 			index = 0;
 		}
-		if ( !isfrontend && index == -1 ) {
+		if (( !isfrontend && index == -1 ) || ( index > nsibs ) ){
 			index = nsibs;
 		}