diff --git a/change_log.txt b/change_log.txt
index 76259be2..fd0d581c 100644
--- a/change_log.txt
+++ b/change_log.txt
@@ -3,7 +3,7 @@
 - bugfix use caching properties of template instead of smarty object when compiling child {block}
 - bugfix {*block}...{/block*} did throw an exception in template inheritance
 - bugfix on template inheritance using nested eval or string resource in {extends} tags
-
+- bugfix on output buffer handling in isCached() method
 
 =====  RC4 =====
 
diff --git a/libs/sysplugins/smarty_internal_cacheresource_file.php b/libs/sysplugins/smarty_internal_cacheresource_file.php
index 3ce4e8fc..c2f9a726 100644
--- a/libs/sysplugins/smarty_internal_cacheresource_file.php
+++ b/libs/sysplugins/smarty_internal_cacheresource_file.php
@@ -76,11 +76,12 @@ class Smarty_Internal_CacheResource_File {
      */
     public function getCachedContents($_template, $no_render = false)
     {
-        ob_start();
+    	if (!$no_render) {
+        	ob_start();
+    	}
         $_smarty_tpl = $_template;
         include $_template->getCachedFilepath();
         if ($no_render) {
-        	ob_clean();
         	return null;
         } else {
           return ob_get_clean();