diff --git a/system/core/Output.php b/system/core/Output.php
index 02f6693..e7d559a 100644
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -674,7 +674,7 @@
 		$cache_info = unserialize($match[1]);
 		$expire = $cache_info['expire'];
 
-		$last_modified = filemtime($cache_path);
+		$last_modified = filemtime($filepath);
 
 		// Has the file expired?
 		if ($_SERVER['REQUEST_TIME'] >= $expire && is_really_writable($cache_path))