diff --git a/README.md b/README.md
index c3455d2..aafc80c 100644
--- a/README.md
+++ b/README.md
@@ -6,3 +6,9 @@ Details at [the blog post](http://ralsina.me/weblog/posts/the-cheapest-server.ht
 
 When adding a new hostname, remember to create a cert for it using
 `flyctl certs create hostname`
+
+Every 90 days the tailscale auth key will expire and you need to set a new one as
+a secret.
+
+* Create the new one at https://login.tailscale.com/admin/settings/keys
+* Configure it using flyctl secrets set TAILSCALE_AUTHKEY={{PASTEKEYHERE}}
diff --git a/nginx.conf b/nginx.conf
index 7220b9a..a3534b7 100644
--- a/nginx.conf
+++ b/nginx.conf
@@ -39,6 +39,7 @@ server {
   server_name faas.ralsina.me;
 
   add_header 'Access-Control-Allow-Origin' '*';
+  add_header 'Access-Control-Allow-Headers' '*';
   add_header 'Access-Control-Allow-Credentials' 'true';
 
   location / {