diff --git a/appservice/message_send_checkpoint.go b/appservice/message_send_checkpoint.go
index 5500e673..2b2ccb16 100644
--- a/appservice/message_send_checkpoint.go
+++ b/appservice/message_send_checkpoint.go
@@ -37,6 +37,8 @@ const (
 	StatusSuccesss    MessageSendCheckpointStatus = "SUCCESS"
 	StatusWillRetry   MessageSendCheckpointStatus = "WILL_RETRY"
 	StatusPermFailure MessageSendCheckpointStatus = "PERM_FAILURE"
+	StatusUnsupported MessageSendCheckpointStatus = "UNSUPPORTED"
+	StatusTimeout     MessageSendCheckpointStatus = "TIMEOUT"
 )
 
 type MessageSendCheckpointReportedBy string