From 064291e902c433268820449526fa11229ef926c0 Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Tue, 12 Aug 2025 16:23:36 -0400
Subject: [PATCH] add an explicit note covering #2289

---
 docs/MANUAL.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/MANUAL.md b/docs/MANUAL.md
index 17cfcc94..59ef6cae 100644
--- a/docs/MANUAL.md
+++ b/docs/MANUAL.md
@@ -171,6 +171,7 @@ Rehashing also reloads TLS certificates and the MOTD. Some configuration setting
 
 Ergo can also be configured using environment variables, using the following technique:
 
+1. Ensure that `allow-environment-variables` is set to `true` in the YAML config file itself (see `default.yaml` for an example)
 1. Find the "path" of the config variable you want to override in the YAML file, e.g., `server.websockets.allowed-origins`
 1. Convert each path component from "kebab case" to "screaming snake case", e.g., `SERVER`, `WEBSOCKETS`, and `ALLOWED_ORIGINS`.
 1. Prepend `ERGO` to the components, then join them all together using `__` as the separator, e.g., `ERGO__SERVER__WEBSOCKETS__ALLOWED_ORIGINS`.