diff --git a/docker-compose.read-only.yml b/docker-compose.read-only.yml
index bbce295f..1b528915 100644
--- a/docker-compose.read-only.yml
+++ b/docker-compose.read-only.yml
@@ -10,7 +10,7 @@ services:
       read-only-db:
         condition: service_healthy
     ports:
-      - "5000:5000"
+      - "${READ_ONLY_WEB_PUBLISH_PORT}:5000"
     environment:
       FLASK_APP: "datalad_registry:create_app"