diff --git a/change_log.txt b/change_log.txt
index dac8484d..120ab868 100644
--- a/change_log.txt
+++ b/change_log.txt
@@ -2,6 +2,7 @@
 21.09.2011
 - bugfix look for mixed case plugin file names as in 3.0 if not found try all lowercase
 - added $error_muting to suppress error messages even for badly implemented error_handlers
+- optimized autoloader
 
 20.09.2011
 - bugfix removed debug echo output while compiling template inheritance
diff --git a/libs/Smarty.class.php b/libs/Smarty.class.php
index bf40e1e0..d3d6abd2 100644
--- a/libs/Smarty.class.php
+++ b/libs/Smarty.class.php
@@ -1209,7 +1209,7 @@ class Smarty extends Smarty_Internal_TemplateBase {
         // loop through plugin dirs and find the plugin
         foreach($this->getPluginsDir() as $_plugin_dir) {
             $names = array(
-                $_plugin_dir . $_plugin_filename,
+                //$_plugin_dir . $_plugin_filename,
                 $_plugin_dir . strtolower($_plugin_filename),
             );
             foreach ($names as $file) {
@@ -1352,19 +1352,20 @@ class SmartyCompilerException extends SmartyException  {
 function smartyAutoload($class)
 {
     $_class = strtolower($class);
-    if (substr($_class, 0, 16) == 'smarty_internal_'
-    || in_array( $_class, array(
-    'smarty_config_source',
-    'smarty_config_compiled',
-    'smarty_security',
-    'smarty_cacheresource',
-    'smarty_cacheresource_custom',
-    'smarty_cacheresource_keyvaluestore',
-    'smarty_resource',
-    'smarty_resource_custom',
-    'smarty_resource_uncompiled',
-    'smarty_resource_recompiled',
-    ))) {
+    $_classes = array(
+        'smarty_config_source' => true,
+        'smarty_config_compiled' => true,
+        'smarty_security' => true,
+        'smarty_cacheresource' => true,
+        'smarty_cacheresource_custom' => true,
+        'smarty_cacheresource_keyvaluestore' => true,
+        'smarty_resource' => true,
+        'smarty_resource_custom' => true,
+        'smarty_resource_uncompiled' => true,
+        'smarty_resource_recompiled' => true,
+    );
+    
+    if (!strncmp($_class, 'smarty_internal_', 16) || isset($_classes[$_class])) {
         include SMARTY_SYSPLUGINS_DIR . $_class . '.php';
     }
 }