diff --git a/library/Icinga/Web/View.php b/library/Icinga/Web/View.php
index f00584f9f..2c80d1d2a 100644
--- a/library/Icinga/Web/View.php
+++ b/library/Icinga/Web/View.php
@@ -99,7 +99,7 @@ class View extends Zend_View_Abstract
     /**
      * Escape the given value top be safely used in view scripts
      *
-     * @param  string $var  The output to be escaped
+     * @param  ?string $var  The output to be escaped
      * @return string
      */
     public function escape($var)