diff --git a/Dockerfile b/Dockerfile
index 5ff16a4..8d46626 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,5 +9,6 @@ COPY package.json package.json
 
 RUN npm install --frozen-lockfile
 
+PORT 80
 ENTRYPOINT [ "/usr/local/bin/node" ]
 CMD [ "index.js" ]