diff --git a/websocket-sharp/Net/NetworkCredential.cs b/websocket-sharp/Net/NetworkCredential.cs
index 4881f59d..73bd0b30 100644
--- a/websocket-sharp/Net/NetworkCredential.cs
+++ b/websocket-sharp/Net/NetworkCredential.cs
@@ -170,6 +170,10 @@ namespace WebSocketSharp.Net
     /// <summary>
     /// Gets the roles associated with the credentials.
     /// </summary>
+    /// <remarks>
+    /// This property returns an empty array if the roles were
+    /// initialized with <see langword="null"/>.
+    /// </remarks>
     /// <value>
     /// An array of <see cref="string"/> that represents the role names
     /// to which the username belongs.