diff --git a/README.md b/README.md
index e55ae164..276e28c1 100644
--- a/README.md
+++ b/README.md
@@ -7,3 +7,12 @@ This is the Dojos service, a backend repository of the [CoderDojo Zen Community
 If you want to get set up to make a backend contribution, please see the [cp-local-development repository](https://github.com/CoderDojo/cp-local-development).
 
 General documentation is in the [community-platform repository](https://github.com/CoderDojo/community-platform).
+
+## Google Maps API key for development
+
+This service needs a Google Maps API key for geolating dojos.  It is set by the environment variable `GOOGLE_MAPS_KEY`.  You should have this in your environment before starting the service.  If you're using the `cp-local-development` repo, you should put it in your `.env` file in that repo before starting the containers.
+
+Rather than share our dev API key here in the repo, you should set up your own key [on the Google Maps API console](https://console.cloud.google.com/google/maps-apis/credentials).  For engineers at the RPF, we have a key there called `Backend Dev Api Key`, and you should add your IP address to the list of permitted addresses there.
+
+**NB** Do not add it to `config/development.env` as you may end up accidentally commiting your key.
+
diff --git a/config/development.env b/config/development.env
index bfd2f312..f4e128a4 100644
--- a/config/development.env
+++ b/config/development.env
@@ -11,5 +11,4 @@ MAIL_PASS=0383c445ef22d4
 
 HOSTNAME=localhost
 
-GOOGLE_MAPS_KEY=AIzaSyAWA2gcHWQsS7Snr_p86QUxGwM0hBn95pQ
 GOOGLE_API_ENABLED=false