diff --git a/servers/slapd/back-ldbm/idl.c b/servers/slapd/back-ldbm/idl.c
index 60828a2610..ef65444c3d 100644
--- a/servers/slapd/back-ldbm/idl.c
+++ b/servers/slapd/back-ldbm/idl.c
@@ -726,12 +726,9 @@ idl_notin(
 	if ( a == NULL ) {
 		return( NULL );
 	}
-	if ( b == NULL ) {
+	if ( b == NULL || ALLIDS( b )) {
 		return( idl_dup( a ) );
 	}
-	if ( ALLIDS( b ) ) {
-		return( NULL );
-	}
 
 	if ( ALLIDS( a ) ) {
 		n = idl_alloc( SLAPD_LDBM_MIN_MAXIDS );