diff --git a/change_log.txt b/change_log.txt
index e94baf5c..7c85e363 100644
--- a/change_log.txt
+++ b/change_log.txt
@@ -3,6 +3,7 @@
   - bugfix assigning a variable in if condition by function like {if $value = array_shift($array)} the function got called twice https://github.com/smarty-php/smarty/issues/291
   - bugfix function plugins called with assign attribute like {foo assign='bar'} did not output returned content because
            because assumption was made that it was assigned to a variable https://github.com/smarty-php/smarty/issues/292
+  - bugfix calling $smarty->isCached() on a not existing cache file with $smarty->cache_locking = true; could cause a 10 second delay http://www.smarty.net/forums/viewtopic.php?t=26282
 
  11.09.2016
   - improvement {math} misleading E_USER_WARNING messages when parameter value = null https://github.com/smarty-php/smarty/issues/288
diff --git a/libs/Smarty.class.php b/libs/Smarty.class.php
index 4b676865..867979de 100644
--- a/libs/Smarty.class.php
+++ b/libs/Smarty.class.php
@@ -114,7 +114,7 @@ class Smarty extends Smarty_Internal_TemplateBase
     /**
      * smarty version
      */
-    const SMARTY_VERSION = '3.1.31-dev/20';
+    const SMARTY_VERSION = '3.1.31-dev/21';
 
     /**
      * define variable scopes
@@ -1103,6 +1103,9 @@ class Smarty extends Smarty_Internal_TemplateBase
         } else {
             $data = null;
         }
+        if (!$this->_templateDirNormalized) {
+            $this->_nomalizeTemplateConfig(false);
+        }
         $_templateId = $this->_getTemplateId($template, $cache_id, $compile_id);
         $tpl = null;
         if ($this->caching && isset($this->_cache[ 'isCached' ][ $_templateId ])) {