diff --git a/docker-compose.yml b/docker-compose.yml
index d9149df..2ac2b4c 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -3,6 +3,7 @@ version: "2"
 services:
   python-app:
     build: .
+    image: python-app:3.9-alpine
     volumes:
       - ./app/:/app
     entrypoint: [python, script.py]