diff --git a/Duplicati/Library/Common/IO/SystemIOWindows.cs b/Duplicati/Library/Common/IO/SystemIOWindows.cs
index d9eaf2c18..4bebd6fbb 100644
--- a/Duplicati/Library/Common/IO/SystemIOWindows.cs
+++ b/Duplicati/Library/Common/IO/SystemIOWindows.cs
@@ -35,6 +35,7 @@ namespace Duplicati.Library.Common.IO
 
         private static bool IsPathTooLong(string path)
         {
+            // Use 258 for length check instead of 260 (MAX_PATH) - we need to leave room for the 16-bit (wide) null terminator
             return path.StartsWith(UNCPREFIX, StringComparison.Ordinal) || path.StartsWith(UNCPREFIX_SERVER, StringComparison.Ordinal) || path.Length > 258;
         }