diff --git a/tinyfilemanager.php b/tinyfilemanager.php
index db8cc1c..718d006 100644
--- a/tinyfilemanager.php
+++ b/tinyfilemanager.php
@@ -2501,7 +2501,8 @@ function fm_get_filesize($size)
 {
     $size = (float) $size;
     $units = array('B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');
-    $power = $size > 0 ? floor(log($size, 1024)) : 0;
+    $power = ($size > 0) ? floor(log($size, 1024)) : 0;
+    $power = ($power > (count($units) - 1)) ? (count($units) - 1) : $power;
     return sprintf('%s %s', round($size / pow(1024, $power), 2), $units[$power]);
 }