diff --git a/usr/local/bin/sh.zio.backup b/usr/local/bin/sh.zio.backup
index 6a85e28..e97b505 100755
--- a/usr/local/bin/sh.zio.backup
+++ b/usr/local/bin/sh.zio.backup
@@ -104,6 +104,7 @@ function invoke_script() {
     export -f forget_backup
     export -f get_config_dir
     export -f get_dump_dir
+    export -f get_random_filename
     export -f get_real_path
     export -f get_secret
     export -f invoke_restic