diff --git a/PVE/API2/ACMEPlugin.pm b/PVE/API2/ACMEPlugin.pm
index e5a81945..92e0dfb6 100644
--- a/PVE/API2/ACMEPlugin.pm
+++ b/PVE/API2/ACMEPlugin.pm
@@ -6,20 +6,21 @@ use warnings;
 use MIME::Base64;
 use Storable qw(dclone);
 
-
 use PVE::ACME::Challenge;
 use PVE::ACME::DNSChallenge;
 use PVE::ACME::StandAlone;
-use PVE::Cluster qw(cfs_read_file cfs_write_file cfs_register_file);
+use PVE::Cluster qw(cfs_read_file cfs_write_file cfs_register_file cfs_lock_file);
 use PVE::JSONSchema qw(register_standard_option get_standard_option);
 use PVE::Tools qw(extract_param);
+
 use base qw(PVE::RESTHandler);
 
-my $FILENAME = "priv/acme/plugins.cfg";
+my $plugin_config_file = "priv/acme/plugins.cfg";
 
-cfs_register_file ($FILENAME,
+cfs_register_file($plugin_config_file,
    sub { PVE::ACME::Challenge->parse_config(@_); },
-   sub { PVE::ACME::Challenge->write_config(@_); });
+   sub { PVE::ACME::Challenge->write_config(@_); },
+);
 
 PVE::ACME::DNSChallenge->register();
 PVE::ACME::StandAlone->register();
@@ -36,8 +37,7 @@ my $plugin_type_enum = PVE::ACME::Challenge->lookup_types();
 my $modify_cfg_for_api = sub {
     my ($cfg, $pluginid) = @_;
 
-    die "ACME plugin '$pluginid' not defined\n"
-	if !defined($cfg->{ids}->{$pluginid});
+    die "ACME plugin '$pluginid' not defined\n" if !defined($cfg->{ids}->{$pluginid});
 
     my $plugin_cfg = dclone($cfg->{ids}->{$pluginid});
     $plugin_cfg->{plugin} = $pluginid;
@@ -59,7 +59,7 @@ __PACKAGE__->register_method ({
 	additionalProperties => 0,
 	properties => {
 	    type => {
-		description => "Only list storage of specific type",
+		description => "Only list ACME plugins of a specific type",
 		type => 'string',
 		enum => $plugin_type_enum,
 		optional => 1,
@@ -81,8 +81,7 @@ __PACKAGE__->register_method ({
 
 	my $cfg = load_config();
 
-	my $res =[];
-
+	my $res = [];
 	foreach my $pluginid (keys %{$cfg->{ids}}) {
 	    my $plugin_cfg = $modify_cfg_for_api->($cfg, $pluginid);
 	    next if $param->{type} && $param->{type} ne $plugin_cfg->{type};
@@ -90,14 +89,14 @@ __PACKAGE__->register_method ({
 	}
 
 	return $res;
-
-    }});
+    }
+});
 
 __PACKAGE__->register_method({
     name => 'get_plugin_config',
     path => '{id}',
     method => 'GET',
-    description => "Get ACME DNS plugin configuration.",
+    description => "Get ACME plugin configuration.",
     permissions => {
 	check => ['perm', '/', [ 'Sys.Modify' ]],
     },
@@ -114,109 +113,104 @@ __PACKAGE__->register_method({
     code => sub {
 	my ($param) = @_;
 
-	return $modify_cfg_for_api->(load_config(), $param->{id});
-    }});
-
-my $update_config = sub {
-    my ($id, $op, $type, $param) = @_;
-
-    my $cfg = load_config();
-
-    if ( $op eq "add" ) {
-	die "Section with ID: $id already exists\n"
-	    if defined($cfg->{ids}->{$id});
-
-	my $plugin = PVE::ACME::Challenge->lookup($type);
-	my $opts = $plugin->check_config($id, $param, 1, 1);
-
-	$cfg->{ids}->{$id} = $opts;
-	$cfg->{ids}->{$id}->{type} = $type;
-    } elsif ($op eq "update") {
-	die "Section with ID; $id does not exist\n"
-	    if !defined($cfg->{ids}->{$id});
-
-	my $delete = extract_param($param, 'delete');
-
-	$type = $cfg->{ids}->{$id}->{type};
-	my $plugin = PVE::ACME::Challenge->lookup($type);
-	my $opts = $plugin->check_config($id, $param, 0, 1);
-	if ($delete) {
-	    my $options = $plugin->private()->{options}->{$type};
-	    foreach my $k (PVE::Tools::split_list($delete)) {
-		my $d = $options->{$k} || die "no such option '$k'\n";
-		die "unable to delete required option '$k'\n" if !$d->{optional};
-		die "unable to delete fixed option '$k'\n" if $d->{fixed};
-		die "cannot set and delete property '$k' at the same time!\n"
-		    if defined($opts->{$k});
-
-		delete $cfg->{ids}->{$id}->{$k};
-	    }
-	}
-
-	for my $k (keys %$opts) {
-	    print "$k: $opts->{$k}\n";
-	    $cfg->{ids}->{$id}->{$k} = $opts->{$k};
-	}
-    } elsif ($op eq "del") {
-	delete $cfg->{ids}->{$id};
-    } else {
-	die 'undefined config update operation\n' if !defined($op);
-	die "unknown config update operation '$op'\n";
+	my $cfg = load_config();
+	return $modify_cfg_for_api->($cfg, $param->{id});
     }
-
-    PVE::Cluster::cfs_write_file($FILENAME, $cfg);
-};
+});
 
 __PACKAGE__->register_method({
     name => 'add_plugin',
     path => '',
     method => 'POST',
-    description => "Add ACME DNS plugin configuration.",
+    description => "Add ACME plugin configuration.",
     permissions => {
 	check => ['perm', '/', [ 'Sys.Modify' ]],
     },
     protected => 1,
     parameters => PVE::ACME::Challenge->createSchema(),
-    returns => { type => "null" },
+    returns => {
+	type => "null"
+    },
     code => sub {
 	my ($param) = @_;
 
 	my $id = extract_param($param, 'id');
 	my $type = extract_param($param, 'type');
 
-	PVE::Cluster::cfs_lock_file($FILENAME, undef, $update_config, $id, "add", $type, $param);
+	cfs_lock_file($plugin_config_file, undef, sub {
+	    my $cfg = load_config();
+	    die "ACME plugin ID '$id' already exists\n" if defined($cfg->{ids}->{$id});
+
+	    my $plugin = PVE::ACME::Challenge->lookup($type);
+	    my $opts = $plugin->check_config($id, $param, 1, 1);
+
+	    $cfg->{ids}->{$id} = $opts;
+	    $cfg->{ids}->{$id}->{type} = $type;
+
+	    cfs_write_file($plugin_config_file, $cfg);
+	});
 	die "$@" if $@;
 
 	return undef;
-    }});
+    }
+});
 
 __PACKAGE__->register_method({
     name => 'update_plugin',
     path => '{id}',
     method => 'PUT',
-    description => "Update ACME DNS plugin configuration.",
+    description => "Update ACME plugin configuration.",
     permissions => {
 	check => ['perm', '/', [ 'Sys.Modify' ]],
     },
     protected => 1,
     parameters => PVE::ACME::Challenge->updateSchema(),
-    returns => { type => "null" },
+    returns => {
+	type => "null"
+    },
     code => sub {
 	my ($param) = @_;
 
 	my $id = extract_param($param, 'id');
+	my $delete = extract_param($param, 'delete');
 
-	PVE::Cluster::cfs_lock_file($FILENAME, undef, $update_config, $id, "update", undef, $param);
+	cfs_lock_file($plugin_config_file, undef, sub {
+	    my $cfg = load_config();
+	    my $plugin_cfg = $cfg->{ids}->{$id};
+	    die "ACME plugin ID '$id' does not exist\n" if !$plugin_cfg;
+
+	    my $type = $plugin_cfg->{type};
+	    my $plugin = PVE::ACME::Challenge->lookup($type);
+
+	    if (defined($delete)) {
+		my $schema = $plugin->private();
+		my $options = $schema->{options}->{$type};
+		for my $k (PVE::Tools::split_list($delete)) {
+		    my $d = $options->{$k} || die "no such option '$k'\n";
+		    die "unable to delete required option '$k'\n" if !$d->{optional};
+
+		    delete $cfg->{ids}->{$id}->{$k};
+		}
+	    }
+
+	    my $opts = $plugin->check_config($id, $param, 0, 1);
+	    for my $k (sort keys %$opts) {
+		$plugin_cfg->{$k} = $opts->{$k};
+	    }
+
+	    cfs_write_file($plugin_config_file, $cfg);
+	});
 	die "$@" if $@;
 
 	return undef;
-    }});
+    }
+});
 
 __PACKAGE__->register_method({
     name => 'delete_plugin',
     path => '{id}',
     method => 'DELETE',
-    description => "Delete ACME DNS plugin configuration.",
+    description => "Delete ACME plugin configuration.",
     permissions => {
 	check => ['perm', '/', [ 'Sys.Modify' ]],
     },
@@ -227,29 +221,31 @@ __PACKAGE__->register_method({
 	    id => get_standard_option('pve-acme-pluginid'),
 	},
     },
-    returns => { type => "null" },
+    returns => {
+	type => "null"
+    },
     code => sub {
 	my ($param) = @_;
 
 	my $id = extract_param($param, 'id');
 
-	PVE::Cluster::cfs_lock_file($FILENAME, undef, $update_config, $id, "del", undef, $param );
+	cfs_lock_file($plugin_config_file, undef, sub {
+	    my $cfg = load_config();
+
+	    delete $cfg->{ids}->{$id};
+
+	    cfs_write_file($plugin_config_file, $cfg);
+	});
 	die "$@" if $@;
 
 	return undef;
-    }});
+    }
+});
 
 sub load_config {
-
-    my $raw = eval { cfs_read_file($FILENAME) };
-    return $raw || {};
-}
-
-sub write_conf {
-    my ($conf) = @_;
-
-    my $raw = PVE::ACME::Challenge->write_config($FILENAME, $conf);
-    cfs_write_file($FILENAME, $raw);
+    my $cfg = {};
+    $cfg = cfs_read_file($plugin_config_file) if -e "/etc/pve/$plugin_config_file";
+    return $cfg;
 }
 
 1;