diff --git a/library/Director/Objects/IcingaObjectImports.php b/library/Director/Objects/IcingaObjectImports.php
index e8d936fe..ce1ef07a 100644
--- a/library/Director/Objects/IcingaObjectImports.php
+++ b/library/Director/Objects/IcingaObjectImports.php
@@ -105,6 +105,7 @@ class IcingaObjectImports implements Iterator, Countable, IcingaConfigRenderer
         }
 
         $this->imports = array();
+        $this->modified = true;
         return $this->add($import);
     }