diff --git a/change_log.txt b/change_log.txt
index 84b2ff78..d0691328 100644
--- a/change_log.txt
+++ b/change_log.txt
@@ -1,4 +1,7 @@
 ===== trunk  =====
+29.09.2011
+- improvement of Smarty_Internal_Config::loadConfigVars() dropped the in_array for index look up
+
 28.09.2011
 - bugfix on template functions called nocache calling other template functions
 
diff --git a/libs/sysplugins/smarty_internal_config.php b/libs/sysplugins/smarty_internal_config.php
index 3a38e212..a309ec9f 100644
--- a/libs/sysplugins/smarty_internal_config.php
+++ b/libs/sysplugins/smarty_internal_config.php
@@ -240,8 +240,9 @@ class Smarty_Internal_Config {
         }
         // scan sections
         if (!empty($sections)) {
+            $sections = array_flip((array) $sections);
             foreach ($_config_vars['sections'] as $this_section => $dummy) {
-                if (in_array($this_section, (array) $sections)) {
+                if (isset($sections[$this_section])) {
                     foreach ($_config_vars['sections'][$this_section]['vars'] as $variable => $value) {
                         if ($this->smarty->config_overwrite || !isset($scope_ptr->config_vars[$variable])) {
                             $scope_ptr->config_vars[$variable] = $value;