diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index be7ac8ee96a3f951d846a44373a9143bbec83bab..9041087fd53a03554cefeb9286c0e82e0cae23e4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,3 +1,5 @@
+image: python:3.9-slim-buster
+
 stages:
   - build
   - deploy
@@ -23,4 +25,4 @@ pages:
     paths:
       - public
   only:
-    - main
+    - master