diff --git a/mise.toml b/mise.toml
index 964cfff..fddb401 100644
--- a/mise.toml
+++ b/mise.toml
@@ -30,9 +30,10 @@ mise run lint ${usage_dir?}
 [tasks.build-luks]
 usage = '''
 arg "<dir>" help="Directory containing the Packer template to build e.g. debian/13-trixie"
+flag "--luks-wait-seconds <seconds>" help="Seconds to wait for the LUKS password prompt after installation before sending the password" default="45"
 '''
 run = '''
-_scripts/unlock-luks-after-install.py -t ${usage_dir?}
+_scripts/unlock-luks-after-install.py -t ${usage_dir?} --luks-wait-seconds ${usage_luks_wait_seconds?}
 '''
 
 [tasks.init]