diff --git a/docs/2.guide/3.going-further/10.runtime-config.md b/docs/2.guide/3.going-further/10.runtime-config.md
index 9974149a8..df74225cd 100644
--- a/docs/2.guide/3.going-further/10.runtime-config.md
+++ b/docs/2.guide/3.going-further/10.runtime-config.md
@@ -56,6 +56,11 @@ There are two key requirements:
 
 1. Only a specially-named environment variable can override a runtime config property. That is, an uppercase environment variable starting with `NUXT_` which uses `_` to separate keys and case changes.
 
+::callout{color="amber" icon="i-ph-warning-duotone"}
+Setting the default of `runtimeConfig` values to *differently named environment variables* (for example setting `myVar` to `process.env.OTHER_VARIABLE`) will only work during build-time and will break on runtime.
+It is advised to use environment variables that match the structure of your `runtimeConfig` object.
+::
+
 #### Example
 
 ```sh [.env]