diff --git a/website/docs/addons/webhook.md b/website/docs/addons/webhook.md
index 9f511f7867..a65f9dc7a7 100644
--- a/website/docs/addons/webhook.md
+++ b/website/docs/addons/webhook.md
@@ -53,3 +53,11 @@ Example:
 ```
 
 If you don't specify anything Unleash will use the [Unleash event format](/api/admin/events).
+
+#### Custom SSL certificates {#certificates}
+
+If your webhook endpoint uses a custom SSL certificate,
+you will need to start Unleash with the `NODE_EXTRA_CA_CERTS` environment variable set.
+It needs to point to your custom certificate file in pem format.
+
+For more information: [see node documentation](https://nodejs.org/api/cli.html#node_extra_ca_certsfile)