diff --git a/change_log.txt b/change_log.txt
index 38d876f7..4661f657 100644
--- a/change_log.txt
+++ b/change_log.txt
@@ -1,4 +1,8 @@
 ===== trunk  =====
+22.08.2012
+- bugfix test MBString availability through mb_split, as it could've been compiled without regex support (--enable-mbregex).
+  Either we get MBstring's full package, or we pretend it's not there at all.
+
 21.08.2012
 - bugfix $auto_literal = false did not work with { block} tags in child templates 
   (problem was reintroduced after fix in 3.1.7)(Forum Topic 20581)
diff --git a/libs/Smarty.class.php b/libs/Smarty.class.php
index 9b46a0da..3c5e806e 100644
--- a/libs/Smarty.class.php
+++ b/libs/Smarty.class.php
@@ -57,7 +57,7 @@ if (!defined('SMARTY_PLUGINS_DIR')) {
     define('SMARTY_PLUGINS_DIR', SMARTY_DIR . 'plugins' . DS);
 }
 if (!defined('SMARTY_MBSTRING')) {
-    define('SMARTY_MBSTRING', function_exists('mb_strlen'));
+    define('SMARTY_MBSTRING', function_exists('mb_split'));
 }
 if (!defined('SMARTY_RESOURCE_CHAR_SET')) {
     // UTF-8 can only be done properly when mbstring is available!