diff --git a/unit-files/backup-u@.service b/unit-files/backup-u@.service
index ba85702052585c0395a469052a85a7acd1e21fd7..f1bb6ba668f6823bd553282b6e7c6da3088ced86 100644
--- a/unit-files/backup-u@.service
+++ b/unit-files/backup-u@.service
@@ -20,6 +20,7 @@ ExecStart=/bin/bash -euxc ' \
   /bin/docker run \
     --rm \
     --name backup-%i \
+    -e PASSPHRASE \
     -h backup.container \
     --cpu-shares=40 \
     -e PASSPHRASE \