diff --git a/VEST/vest.sql b/VEST/vest.sql
index 561241a20..9d4b9397f 100644
--- a/VEST/vest.sql
+++ b/VEST/vest.sql
@@ -123,7 +123,7 @@ CREATE OR REPLACE PROCEDURE vest_update_perslid (
          AND p.prs_perslid_oslogin IS NOT NULL
          AND i.prs_perslid_oslogin IS NULL
          AND p.prs_perslid_verwijder IS NULL
-         AND substr (p.prs_perslid_oslogin, 1, 1) != '_'
+         AND p.prs_perslid_oslogin NOT LIKE '%_%'
       ORDER BY 2;
 
   v_count           NUMBER;