diff --git a/onyx/include/admin/exercice.php b/onyx/include/admin/exercice.php
index b007d591..1259b9f5 100644
--- a/onyx/include/admin/exercice.php
+++ b/onyx/include/admin/exercice.php
@@ -45,6 +45,7 @@ try
       }
 
       $exercice->update();
+      Cache::del("ordered_th".$exercice->theme->get_id());
       header("Location: /".implode("/", $p));
       exit();
     }