diff --git a/NEWS b/NEWS
index fd37976b..bff5c989 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,4 @@
+  - add "null" as a valid token for {if} when security is enabled (messju)
   - add javascript_charcode encoding option to mailto function
     (monte)
   - add ids to html_radios labels (monte, menulis)
diff --git a/libs/Smarty.class.php b/libs/Smarty.class.php
index 506c6b2e..755c173e 100644
--- a/libs/Smarty.class.php
+++ b/libs/Smarty.class.php
@@ -232,7 +232,7 @@ class Smarty
                                                                'isset', 'empty',
                                                                'count', 'sizeof',
                                                                'in_array', 'is_array',
-                                                               'true','false'),
+                                                               'true', 'false', 'null'),
                                     'INCLUDE_ANY'     => false,
                                     'PHP_TAGS'        => false,
                                     'MODIFIER_FUNCS'  => array('count'),