diff --git a/Server/Core/Helper/Helper.cs b/Server/Core/Helper/Helper.cs
index 2f0e1751..d37fbbb8 100644
--- a/Server/Core/Helper/Helper.cs
+++ b/Server/Core/Helper/Helper.cs
@@ -9,6 +9,7 @@ public static class Helper
     {
         private const string CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
         private static readonly Random _rnd = new Random(Environment.TickCount);
+        private const string[] sizes = { "B", "KB", "MB", "GB" };
 
         public static string GetRandomFilename(int length, string extension)
         {
@@ -30,7 +31,6 @@ public static string GetRandomName(int length)
 
         public static string GetFileSize(long size)
         {
-            string[] sizes = {"B", "KB", "MB", "GB"};
             double len = size;
             int order = 0;
             while (len >= 1024 && order + 1 < sizes.Length)