diff --git a/docs/basic-features/environment-variables.md b/docs/basic-features/environment-variables.md
index d68a614627ed0..5001c080d40c7 100644
--- a/docs/basic-features/environment-variables.md
+++ b/docs/basic-features/environment-variables.md
@@ -93,7 +93,8 @@ This loads `process.env.NEXT_PUBLIC_ANALYTICS_ID` into the Node.js environment a
 // pages/index.js
 import setupAnalyticsService from '../lib/my-analytics-service'
 
-// NEXT_PUBLIC_ANALYTICS_ID can be used here as it's prefixed by NEXT_PUBLIC_
+// 'NEXT_PUBLIC_ANALYTICS_ID' can be used here as it's prefixed by 'NEXT_PUBLIC_'.
+// It will be transformed at build time to `setupAnalyticsService('abcdefghijk')`.
 setupAnalyticsService(process.env.NEXT_PUBLIC_ANALYTICS_ID)
 
 function HomePage() {
@@ -103,6 +104,18 @@ function HomePage() {
 export default HomePage
 ```
 
+Note that dynamic lookups will _not_ be inlined, such as:
+
+```js
+// This will NOT be inlined, because it uses a variable
+const varName = 'NEXT_PUBLIC_ANALYTICS_ID'
+setupAnalyticsService(process.env[varName])
+
+// This will NOT be inlined, because it uses a variable
+const env = process.env
+setupAnalyticsService(env.NEXT_PUBLIC_ANALYTICS_ID)
+```
+
 ## Default Environment Variables
 
 In general only one `.env.local` file is needed. However, sometimes you might want to add some defaults for the `development` (`next dev`) or `production` (`next start`) environment.