diff --git a/workflow/engine/classes/class.wsBase.php b/workflow/engine/classes/class.wsBase.php
index ff4cb1fdf..2c16b9817 100755
--- a/workflow/engine/classes/class.wsBase.php
+++ b/workflow/engine/classes/class.wsBase.php
@@ -1965,7 +1965,7 @@ class wsBase
       $tasUid = $aRow['TAS_UID'];
       $derivation = new Derivation ();
       $userList   = $derivation->getAllUsersFromAnyTask( $tasUid );
-      if ( in_array ( $userIdTarget, $userList ) ) {
+      if ( !in_array ( $userIdTarget, $userList ) ) {
         $result = new wsResponse (34, G::loadTranslation ('ID_TARGET_USER_DOES_NOT_HAVE_RIGHTS') );
         return $result;
       }