diff --git a/README.md b/README.md
index 73d6f14..3ea684e 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ If you're using git to get this repo you should use `git submodule update --init
 Install the dependencies using `yarn install`.  
 Then you should be able to run the app with `yarn start`.
 
-You can change the default port by setting the environment variable `PORT` to any other number
+You can change the default port by setting the environment variable `PORT` to any other number before starting the app.
 
 ## Building the app
 Make sure you've installed the dependencies for all packages (the root folder, `server` and `webui`).