diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index aadfde58..c0a72c03 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -243,6 +243,7 @@ my $check_vm_modify_config_perm = sub {
 	# disk checks need to be done somewhere else
 	next if PVE::QemuServer::is_valid_drivename($opt);
 	next if $opt eq 'cdrom';
+	next if $opt =~ m/^unused\d+$/;
 
 	if ($cpuoptions->{$opt} || $opt =~ m/^numa\d+$/) {
 	    $rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Config.CPU']);
diff --git a/changelog.Debian b/changelog.Debian
index d6685751..a06c4213 100644
--- a/changelog.Debian
+++ b/changelog.Debian
@@ -2,6 +2,8 @@ qemu-server (4.0-80) unstable; urgency=medium
 
   * split old style pipe open call
 
+  * fix unnecessary root check for unused disks
+
  -- Proxmox Support Team <support@proxmox.com>  Thu, 09 Jun 2016 18:13:03 +0200
 
 qemu-server (4.0-79) unstable; urgency=medium