diff --git a/extend/base/helper.php b/extend/base/helper.php
index d16b4a5..9777d3c 100644
--- a/extend/base/helper.php
+++ b/extend/base/helper.php
@@ -411,7 +411,7 @@ function format_bytes($size, $delimiter = '')
     if (is_null($size)) {
         return '0B';
     }
-    $units = ['B', 'KB', 'MB', 'GB', 'TB', 'PB'];
+    $units = ['B', 'K', 'M', 'G', 'T', 'P'];
     for ($i = 0; $size >= 1024 && $i < 5; $i++) {
         $size /= 1024;
     }
@@ -426,23 +426,18 @@ function parse_bytes($size)
         case 'b':
             break;
         case 'k':
-        case 'kb':
             $size *= 1024;
             break;
         case 'm':
-        case 'mb':
             $size *= 1024 * 1024;
             break;
         case 'g':
-        case 'gb':
             $size *= 1024 * 1024 * 1024;
             break;
         case 't':
-        case 'tb':
             $size *= 1024 * 1024 * 1024 * 1024;
             break;
         case 'p':
-        case 'pb':
             $size *= 1024 * 1024 * 1024 * 1024 * 1024;
             break;
         default: