diff --git a/src/bref/README.md b/src/bref/README.md
index a0a7e41e..12c1e533 100644
--- a/src/bref/README.md
+++ b/src/bref/README.md
@@ -31,27 +31,33 @@ Define the environment variable `APP_RUNTIME` for your application on Lambda.
 
 ## How to use
 
-You need the extra lambda layer `arn:aws:lambda:[region]:403367587399:layer:bref-sf-runtime:1`
-in serverless.yml.
-
-```yaml
-# serverless.yml
-
-# ...
-
-functions:
-    app:
-        handler: public/index.php
-        timeout: 8
-        layers:
-            - ${bref:layer.php-74}
-            - arn:aws:lambda:eu-central-1:403367587399:layer:bref-sf-runtime:1
-        events:
-            -   httpApi: '*'
+You need a new "bootstrap" file for AWS Lambda. That file should look like
+[this](https://github.com/brefphp/extra-php-extensions/blob/master/layers/symfony-runtime/bootstrap).
+The simplest way is to use the `${bref-extra:symfony-runtime-php-80}` from the
+[bref/extra-php-extension package](https://github.com/brefphp/extra-php-extensions).
+
+```diff
+ # serverless.yml
+
+ # ...
+
+ functions:
+     app:
+         handler: public/index.php
+         timeout: 8
+         layers:
+             - ${bref:layer.php-74}
++            - ${bref-extra:symfony-runtime-php-80}
+         events:
+             -   httpApi: '*'
 ```
 
+(You may also copy that bootstrap file yourself and place it in your project root.)
+
 ### Symfony application
 
+Use the standard Symfony 5.3+ index.php.
+
 ```php
 // public/index.php
 
@@ -64,7 +70,6 @@ return function (array $context) {
 };
 ```
 
-
 ### PSR-15 application
 
 ```php
@@ -120,6 +125,8 @@ to serverless.yml
 
 ### Console application
 
+Use the standard Symfony 5.3+ bin/console.
+
 ```php
 // bin/console