diff --git a/irc/handlers.go b/irc/handlers.go
index d4ae95e6..805b8121 100644
--- a/irc/handlers.go
+++ b/irc/handlers.go
@@ -2930,6 +2930,6 @@ func unknownCommandHandler(server *Server, client *Client, msg ircmsg.IrcMessage
 
 // fake handler for invalid utf8
 func invalidUtf8Handler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *ResponseBuffer) bool {
-	rb.Add(nil, server.name, ERR_UNKNOWNERROR, client.Nick(), utils.SafeErrorParam(msg.Command), client.t("Message rejected for containing invalid UTF-8"))
+	rb.Add(nil, server.name, "FAIL", utils.SafeErrorParam(msg.Command), "INVALID_UTF8", client.t("Message rejected for containing invalid UTF-8"))
 	return false
 }