diff --git a/readme.md b/readme.md
index 8077edae..563b637c 100644
--- a/readme.md
+++ b/readme.md
@@ -117,9 +117,11 @@ Add this to the site config file on your Apache server after you have changed th
For this to work you must enable at least the following mods using `a2enmod`:
- `ssl`
- - `proxy_module`
- - `proxy_wstunnel_module`
- - `rewrite_module`
+ - `proxy`
+ - `proxy_http`
+ - `proxy_balancer`
+ - `proxy_wstunnel`
+ - `rewrite`
```bash
@@ -144,6 +146,26 @@ For this to work you must enable at least the following mods using `a2enmod`:
```
+Some SSL certificates like those signed by Let's Encrypt require ACME validation. To allow Let's Encrypt to write and confirm
+the ACME challenge, edit your VirtualHost definition to prevent proxying traffic that queries `/.well-known` and instead
+serve that directly:
+```bash
+
+ # ...
+
+ # create the directory structure /.well-known/acme-challenges
+ # within DocumentRoot and give the HTTP user recursive write
+ # access to it.
+ DocumentRoot /path/to/local/directory
+
+ ProxyPreserveHost On
+ ProxyPass /.well-known !
+ ProxyPass / http://localhost:/
+
+ # ...
+
+```
+
### SWAG Reverse Proxy