diff --git a/src/SharpCompress/Writers/Zip/ZipWriter.cs b/src/SharpCompress/Writers/Zip/ZipWriter.cs
index 725d7f3a..2359d074 100644
--- a/src/SharpCompress/Writers/Zip/ZipWriter.cs
+++ b/src/SharpCompress/Writers/Zip/ZipWriter.cs
@@ -807,6 +807,8 @@ public class ZipWriter : AbstractWriter
 
     /// <summary>
     /// A stream wrapper that doesn't dispose the underlying stream when disposed.
+    /// This is used in encryption scenarios where the crypto stream would otherwise
+    /// dispose the counting stream prematurely, before we can read the final count.
     /// </summary>
     private class NonDisposingStream : Stream
     {