diff --git a/src/Pluf/Middleware/Debug.php b/src/Pluf/Middleware/Debug.php
index 7487a46..d91ac98 100644
--- a/src/Pluf/Middleware/Debug.php
+++ b/src/Pluf/Middleware/Debug.php
@@ -96,7 +96,7 @@ class Pluf_Middleware_Debug
 // -->
   </script>';
         $text = '<pre style="text-align: left;">';
-        $text .= 'Peak mem: '.(int)(xdebug_peak_memory_usage()/1024).'kB'."\n";
+        $text .= 'Peak mem: '.(int)(memory_get_peak_usage()/1024).'kB'."\n";
         $text .= 'Exec time: '.sprintf('%.5f', (microtime(true) - $GLOBALS['_PX_starttime'])).'s'."\n";
         $included_files = get_included_files();
         sort($included_files);