diff --git a/DNS-manual-mode.md b/DNS-manual-mode.md
index 45c8cd7..ae0872c 100644
--- a/DNS-manual-mode.md
+++ b/DNS-manual-mode.md
@@ -29,4 +29,8 @@ acme.sh --issue -d example.com --dns \
 acme.sh --renew -d example.com \
   --yes-I-know-dns-manual-mode-enough-go-ahead-please
 
-```
\ No newline at end of file
+```
+
+
+Known issues:
+[The supported validation types are: dns-01 , but you specified: http-01](https://github.com/Neilpang/acme.sh/issues/1433)
\ No newline at end of file