diff --git a/src/PVE/API2/Storage/Content.pm b/src/PVE/API2/Storage/Content.pm
index 3b73e90..03cc4a1 100644
--- a/src/PVE/API2/Storage/Content.pm
+++ b/src/PVE/API2/Storage/Content.pm
@@ -6,6 +6,7 @@ use warnings;
 use PVE::SafeSyslog;
 use PVE::Cluster;
 use PVE::Storage;
+use PVE::Storage::Plugin; # for 'pve-storage-format' format
 use PVE::INotify;
 use PVE::Exception qw(raise_param_exc);
 use PVE::RPCEnvironment;
@@ -179,7 +180,7 @@ __PACKAGE__->register_method ({
 	    },
 	    'format' => {
 		type => 'string',
-		enum => ['raw', 'qcow2', 'subvol'],
+		format => 'pve-storage-format',
 		requires => 'size',
 		optional => 1,
 	    },