diff --git a/bundles/mailserver/metadata.py b/bundles/mailserver/metadata.py
index 950e7dc..bc82537 100644
--- a/bundles/mailserver/metadata.py
+++ b/bundles/mailserver/metadata.py
@@ -33,13 +33,13 @@ defaults = {
                 'mountpoint': '/var/vmail',
                 'compression': 'on',
                 'atime': 'off',
-                'recordsize': '16K',
+                'recordsize': '16384',
             },
             'tank/vmail/index': {
                 'mountpoint': '/var/vmail/index',
                 'compression': 'on',
                 'atime': 'off',
-                'recordsize': '4K',
+                'recordsize': '4096',
                 'com.sun:auto-snapshot': 'false',
                 'backup': False,
             },