diff --git a/library/Director/CustomVariable/CustomVariable.php b/library/Director/CustomVariable/CustomVariable.php
index 9f620a1b..4a824cf4 100644
--- a/library/Director/CustomVariable/CustomVariable.php
+++ b/library/Director/CustomVariable/CustomVariable.php
@@ -45,12 +45,17 @@ abstract class CustomVariable implements IcingaConfigRenderer
     }
 
     // TODO: implement delete()
-
     public function hasBeenDeleted()
     {
         return $this->deleted;
     }
 
+    public function delete()
+    {
+        $this->deleted = true;
+        return $this;
+    }
+
     // TODO: abstract
     public function getDbValue()
     {