diff --git a/servers/slapd/back-mdb/init.c b/servers/slapd/back-mdb/init.c
index 41fc4068bb..b757700505 100644
--- a/servers/slapd/back-mdb/init.c
+++ b/servers/slapd/back-mdb/init.c
@@ -182,7 +182,7 @@ mdb_db_open( BackendDB *be, ConfigReply *cr )
 		goto fail;
 	}
 
-	rc = mdb_txn_begin( mdb->mi_dbenv, NULL, 0, &txn );
+	rc = mdb_txn_begin( mdb->mi_dbenv, NULL, flags & MDB_RDONLY, &txn );
 	if ( rc ) {
 		Debug( LDAP_DEBUG_ANY,
 			LDAP_XSTRING(mdb_db_open) ": database \"%s\" cannot be opened, err %d. "