diff --git a/Security-Configuration.md b/Security-Configuration.md
index 8988a85..8b28d95 100644
--- a/Security-Configuration.md
+++ b/Security-Configuration.md
@@ -104,10 +104,10 @@ certstrap request-cert --common-name volume01
 certstrap request-cert --common-name master01
 certstrap request-cert --common-name filer01
 certstrap request-cert --common-name client01
-certstrap sign --CA "SeaweedFS CA" volume01
-certstrap sign --CA "SeaweedFS CA" master01
-certstrap sign --CA "SeaweedFS CA" filer01
-certstrap sign --CA "SeaweedFS CA" client01
+certstrap sign --expires "2 years" --CA "SeaweedFS CA" volume01
+certstrap sign --expires "2 years" --CA "SeaweedFS CA" master01
+certstrap sign --expires "2 years" --CA "SeaweedFS CA" filer01
+certstrap sign --expires "2 years" --CA "SeaweedFS CA" client01
 ```
 
 Here is my `security.toml` file content: