diff --git a/manifests/cron/db_purge.pp b/manifests/cron/db_purge.pp
index 274c71a..3bd6796 100644
--- a/manifests/cron/db_purge.pp
+++ b/manifests/cron/db_purge.pp
@@ -77,7 +77,7 @@ class watcher::cron::db_purge (
   $user                             = $::watcher::params::user,
   $age                              = 30,
   $destination                      = '/var/log/watcher/watcher-rowsflush.log',
-  $maxdelay                         = 0,
+  Integer[0] $maxdelay              = 0,
   Boolean $exclude_orphans          = false,
   $max_number                       = undef,
 ) inherits watcher::params {