diff --git a/roles/backup/tasks/main.yml b/roles/backup/tasks/main.yml
index 99f246de94523686618fd8ca6589a63364d47ac0..d4f756b5a9b53fee2b25f9d5577311219ff79b82 100644
--- a/roles/backup/tasks/main.yml
+++ b/roles/backup/tasks/main.yml
@@ -6,7 +6,7 @@
     dest: "/etc/duply/main/patterns/{{ backup_patterns_filename }}"
     owner: root
     group: root
-    mode: 0600
+    mode: "0600"
   notify:
     - Assemble Duply include patterns