diff --git a/documentation/docs/Developers_and_Administrators/How-to-deploy-Codabench-on-your-server.md b/documentation/docs/Developers_and_Administrators/How-to-deploy-Codabench-on-your-server.md
index fb2895b7d..aa11532d4 100644
--- a/documentation/docs/Developers_and_Administrators/How-to-deploy-Codabench-on-your-server.md
+++ b/documentation/docs/Developers_and_Administrators/How-to-deploy-Codabench-on-your-server.md
@@ -439,4 +439,7 @@ Caddyfile :
       path /{$AWS_STORAGE_BUCKET_NAME}* /{$AWS_STORAGE_PRIVATE_BUCKET_NAME}*
     }
     reverse_proxy @min_bucket minio:{$MINIO_PORT}
-```
\ No newline at end of file
+```
+
+## Codabench Instance behind a reverse proxy
+If you put your instance behind a reverse proxy and want that proxy to contact the instance via http or https, your `DOMAIN_NAME` might not be reachable from the outside. In this case, you can set `DOMAIN_NAME` as your internal domain name, used by the reverse proxy, and `EXTERNAL_DOMAIN_NAME` as the domain name that is known on external networks (like the internet).
\ No newline at end of file
diff --git a/src/settings/base.py b/src/settings/base.py
index ed5b978d7..127b17eb8 100644
--- a/src/settings/base.py
+++ b/src/settings/base.py
@@ -19,15 +19,21 @@
 csrf_https_domain = "https://" + os.environ.get("DOMAIN_NAME").split(':')[0]
 csrf_http_domain = "http://" + os.environ.get("DOMAIN_NAME").split(':')[0]
 
-CSRF_TRUSTED_ORIGINS = [csrf_https_domain, csrf_http_domain]
-CSRF_ALLOWED_ORIGINS = [csrf_https_domain, csrf_http_domain]
+if os.environ.get("EXTERNAL_DOMAIN_NAME", "") != "":
+    csrf_https_external_domain = "https://" + os.environ.get("EXTERNAL_DOMAIN_NAME", "").split(':')[0]
+    csrf_http_external_domain = "http://" + os.environ.get("EXTERNAL_DOMAIN_NAME", "").split(':')[0]
+    CSRF_TRUSTED_ORIGINS = [csrf_https_domain, csrf_http_domain, csrf_https_external_domain, csrf_http_external_domain]
+    CSRF_ALLOWED_ORIGINS = [csrf_https_domain, csrf_http_domain, csrf_https_external_domain, csrf_http_external_domain]
 
-SITE_ID = 1
+    DOMAIN_NAME = os.environ.get('EXTERNAL_DOMAIN_NAME').split(':')[0]
+else:
+    CSRF_TRUSTED_ORIGINS = [csrf_https_domain, csrf_http_domain]
+    CSRF_ALLOWED_ORIGINS = [csrf_https_domain, csrf_http_domain]
 
-SITE_DOMAIN = os.environ.get('SITE_DOMAIN', 'http://localhost')
-DOMAIN_NAME = os.environ.get('DOMAIN_NAME', 'localhost').split(':')[0]
+    DOMAIN_NAME = os.environ.get('DOMAIN_NAME', 'localhost').split(':')[0]
 
-SELENIUM_HOSTNAME = os.environ.get("SELENIUM_HOSTNAME", "localhost")
+SITE_DOMAIN = os.environ.get('SITE_DOMAIN', 'http://localhost')
+SITE_ID = 1
 
 
 THIRD_PARTY_APPS = (