diff --git a/modules/backend/formwidgets/Relation.php b/modules/backend/formwidgets/Relation.php
index c5ece5ad3..16c576ff1 100644
--- a/modules/backend/formwidgets/Relation.php
+++ b/modules/backend/formwidgets/Relation.php
@@ -73,7 +73,7 @@ class Relation extends FormWidgetBase
         if (!$this->model->hasRelation($this->relationName)) {
             throw new SystemException(Lang::get(
                 'backend::lang.model.missing_relation',
-                ['class'=>get_class($this->controller), 'relation'=>$this->relationName]
+                ['class'=>get_class($this->model), 'relation'=>$this->relationName]
             ));
         }
     }