diff --git a/Dockerfile b/Dockerfile
index b19c70f..2bb1cab 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,6 +8,7 @@ ENV GITEA__database__PASSWD=${DATABASE_PASSWORD}
 
 ENV GITEA_CUSTOM=/var/lib/gitea/custom
 
-ENV DATABASE_URL='db:5432'
+ARG DATABASE_URL='db:5432'
+ENV DATABASE_URL=${DATABASE_URL}
 
 COPY app.ini /var/lib/gitea/custom/conf/app.ini