diff --git a/include/simpleplugin/class_Attribute.inc b/include/simpleplugin/class_Attribute.inc
index 77e938a538b89cbfa13d2f6f99d35a9ceee58dba..213415a460cc4b04d17d15e1d0915a11908ae271 100644
--- a/include/simpleplugin/class_Attribute.inc
+++ b/include/simpleplugin/class_Attribute.inc
@@ -909,6 +909,10 @@ class ObjectLinkAttribute extends DisplayLDAPAttribute
 
   function renderFormInput ()
   {
+    if (empty($this->value)) {
+      return '';
+    }
+
     try {
       return objects::link($this->value, $this->type);
     } catch (NonExistingLdapNodeException $e) {