diff --git a/docusaurus/docs/adding-custom-environment-variables.md b/docusaurus/docs/adding-custom-environment-variables.md
index 0e635f6a3c0..97fc21fd11d 100644
--- a/docusaurus/docs/adding-custom-environment-variables.md
+++ b/docusaurus/docs/adding-custom-environment-variables.md
@@ -117,6 +117,8 @@ REACT_APP_NOT_SECRET_CODE=abcdef
 
 > Note: You must create custom environment variables beginning with `REACT_APP_`. Any other variables except `NODE_ENV` will be ignored to avoid [accidentally exposing a private key on the machine that could have the same name](https://github.com/facebook/create-react-app/issues/865#issuecomment-252199527). Changing any environment variables will require you to restart the development server if it is running.
 
+> Note: You need to restart the development server after changing `.env` files.
+
 `.env` files **should be** checked into source control (with the exclusion of `.env*.local`).
 
 ### What other `.env` files can be used?