diff --git a/README.md b/README.md
index fe7f8da..eff442f 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,7 @@ The following environment variables should be set:
 - `DJANGO_DATABASE_PASSWORD`: the password of the PostgreSQL user to login as
 - `DJANGO_LANGUAGE_CODE`: the language to use in the dynamic pages
 - `DJANGO_TIME_ZONE`: the timezone to use in the display of datetimes
+- `DJANGO_SETTINGS_MODULE`: should always be `sophon.settings`
 
 ## Development