diff --git a/nginx/ssl_setup.md b/nginx/ssl_setup.md
index 4f32877..9efdab8 100644
--- a/nginx/ssl_setup.md
+++ b/nginx/ssl_setup.md
@@ -32,3 +32,8 @@ server {
 - Profit! http gets forbidden with the first block, and https works with the
   second bit.
 
+Also, this
+link (https://stackoverflow.com/questions/63359785/how-to-use-porkbun-ssl-certificate-files-with-nginx)
+has the mapping between how key files are named in nginx and porkbun. It's
+pretty easy to forget the mapping.
+