diff --git a/apps/docs/content/php/how-to/customize-runtime.mdx b/apps/docs/content/php/how-to/customize-runtime.mdx
index ba74d975..86d6e1cd 100644
--- a/apps/docs/content/php/how-to/customize-runtime.mdx
+++ b/apps/docs/content/php/how-to/customize-runtime.mdx
@@ -50,3 +50,23 @@ To invalidate the custom runtime cache go to `yyy`
 **// TODO screenshot**
 
 When the custom runtime cache is used, Zerops doesn't create a prepare runtime container and executes the deployment of your application directly.
+
+### Overwrite php.ini files
+
+You can override PHP configuration directives by setting environment variables in your `zerops.yml` file.
+
+Here's an example of how to adjust PHP's `post_max_size` directive:
+
+```yml
+zerops:
+  # define hostname of your service
+  - setup: app
+    # ==== how to build your application ====
+    run:
+      # REQUIRED. Sets the base technology for the build environment:
+      base: php-nginx@8.3
+
+      # OPTIONAL. Defines the env variables for the build environment:
+      envVariables:
+        PHP_INI_post_max_size: 10M
+```