diff --git a/src/PVE/JSONSchema.pm b/src/PVE/JSONSchema.pm
index 793ec60..aa82167 100644
--- a/src/PVE/JSONSchema.pm
+++ b/src/PVE/JSONSchema.pm
@@ -105,6 +105,14 @@ register_standard_option('fingerprint-sha256', {
     pattern => '([A-Fa-f0-9]{2}:){31}[A-Fa-f0-9]{2}',
 });
 
+register_standard_option('pve-output-format', {
+    type => 'string',
+    description => 'Output format.',
+    enum => [ 'text', 'plain', 'json' ],
+    optional => 1,
+    default => 'text',
+});
+
 my $format_list = {};
 
 sub register_format {