diff --git a/roles/docker_s3_backup/tasks/main.yml b/roles/docker_s3_backup/tasks/main.yml
index 36e655e..57e5d7a 100644
--- a/roles/docker_s3_backup/tasks/main.yml
+++ b/roles/docker_s3_backup/tasks/main.yml
@@ -71,10 +71,10 @@
 
 # TODO: do this in a more native way rather than a python script reading env vars.
 - name: Determine which backups should be deleted.
-  script: scripts/determine-s3-keys-to-delete.py
+  ansible.builtin.script: scripts/determine-s3-keys-to-delete.py
   environment:
     S3_RESULTS: "{{ s3_list_outputs.results }}"
-    NUM_BACKUPS_TO_KEEP: "{{ docker_backup_retain_count}}"
+    NUM_BACKUPS_TO_KEEP: "{{ docker_backup_retain_count }}"
   register: python_output
   changed_when: false