diff --git a/README.md b/README.md
index 8942275..3792448 100644
--- a/README.md
+++ b/README.md
@@ -58,7 +58,7 @@ You can increase the `frag_duration` (microseconds) to slightly reduce the file
 ## TLS
 Unfortunately, QUIC mandates TLS and makes local development difficult.
 
-If you have a valid certificate you can use it instead of self-signing. The go binaries take a `-cert` and `-key` argument. Skip the remaining steps in this section.
+If you have a valid certificate you can use it instead of self-signing. The go binaries take a `-tls-cert` and `-tls-key` argument. Skip the remaining steps in this section and use your hostname instead.
 
 Otherwise, use [mkcert](https://github.com/FiloSottile/mkcert) to install a self-signed CA:
 ```
@@ -76,7 +76,7 @@ go run main.go
 ```
 
 ## Web Player
-The web assets need to be hosted with a HTTPS server. If you're using a self-signed certificate, you will need to ignore the security warning in Chrome (Advanced -> proceed to localhost). This can be avoided by adding your certificate to the root CA but I'm too lazy to do that.
+The web assets need to be hosted with a HTTPS server. If you're using a self-signed certificate, you may need to ignore the security warning in Chrome (Advanced -> proceed to localhost).
 
 ```
 cd player
@@ -86,6 +86,8 @@ yarn serve
 
 These can be accessed on `https://127.0.0.1:4444` by default.
 
+If you use a custom domain for the Warp server, make sure to override the server URL with the `url` query string parameter, e.g. `https://localhost:4444/?url=https://warp.demo`.
+
 ## Chrome
 Now we need to make Chrome accept these certificates, which normally would involve trusting a root CA but this was not working with WebTransport when I last tried.
 
@@ -94,4 +96,4 @@ Instead, we need to run a *fresh instance* of Chrome, instructing it to allow ou
 Launch a new instance of Chrome Canary:
 ```
 /Applications/Google\ Chrome\ Canary.app/Contents/MacOS/Google\ Chrome\ Canary --allow-insecure-localhost --origin-to-force-quic-on=127.0.0.1:4443 https://127.0.0.1:4444
-```
+```
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