diff --git a/PVE/NodeConfig.pm b/PVE/NodeConfig.pm
index 07fb1434..84a6237d 100644
--- a/PVE/NodeConfig.pm
+++ b/PVE/NodeConfig.pm
@@ -87,6 +87,7 @@ my $acme_domain_desc = {
 	format => 'pve-acme-domain',
 	format_description => 'domain',
 	description => 'domain for this node\'s ACME certificate',
+	default_key => 1,
     },
     plugin => {
 	type => 'string',