diff --git a/DiscordDelete/Program.cs b/DiscordDelete/Program.cs
index 504ccf9..f0733d7 100644
--- a/DiscordDelete/Program.cs
+++ b/DiscordDelete/Program.cs
@@ -25,6 +25,8 @@ int finalCode = await CommandLine
                     .Messages
                     // Skip ones that are already deleted.
                     .Where(message => message.LastHttpCode != 204)
+                    // Skip BadRequest (such as archived thread).
+                    .Where(message => message.LastHttpCode != 400)
                     // Skip NotFound.
                     .Where(message => message.LastHttpCode != 404)
             )