diff --git a/unit-files/backup@.service b/unit-files/backup@.service
index 3c8951e2ac6e69cccb78e5e7328ab74276d029ab..7c631ad2e707e070e2d3b28d425e5a9d202b8caf 100644
--- a/unit-files/backup@.service
+++ b/unit-files/backup@.service
@@ -33,6 +33,7 @@ ExecStart=/bin/bash -euxc ' \
     -h backup.container \
     -v /root:/root \
     -v /data/domains/%i:/backup pierreozoux/duplicity \
+      --full-if-older-than 1W \
       --encrypt-key ${ENCRYPT_KEY} \
         /backup \
         sftp://${BACKUP_DESTINATION}/%i'