diff --git a/docker-compose.yml b/docker-compose.yml
index c576f9f..7ec905f 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -15,7 +15,7 @@ services:
   nanodrop:
     build: .
     ports:
-      - "${PORT:-3000}:3000"
+      - "${PORT:-3000}:${PORT:-3000}"
     environment: { <<: *env }
     volumes:
       - nanodrop-data:/app/data