diff --git a/api/v1/config/instances/add/index.php b/api/v1/config/instances/add/index.php
index 54164e8..df39eb4 100644
--- a/api/v1/config/instances/add/index.php
+++ b/api/v1/config/instances/add/index.php
@@ -13,6 +13,6 @@ if (isset($data['error']))
 $software = trim($_GET['software']);
 $instance = trim($_GET['instance']);
 
-filedb_put("instances/$software/$instance/config");
+filedb_put("instances/$software/$instance", 'config');
 $uri = preg_replace('#api/v1/config/instances.*#', '', $_SERVER['REQUEST_URI']);
 header('Location: '.$uri.'#home');
diff --git a/index.php b/index.php
index 32475d6..d01abc5 100644
--- a/index.php
+++ b/index.php
@@ -16,8 +16,8 @@
 window.consts = {
 	'instance_config': {
 		'mastodon': {
-			'musthave': ['instance_url','psql_host','psql_port','psql_db',
-				'psql_username','psql_password','redis_host','redis_port','api_authkey'],
+			'fields': ['*instance_url','*psql_host','*psql_port','*psql_db',
+				'*psql_username','*psql_password','redis_host','redis_port','*api_authkey'],
 		},
 	}
 };
diff --git a/views/add.php b/views/add.php
index 2402034..7a76242 100644
--- a/views/add.php
+++ b/views/add.php
@@ -17,8 +17,10 @@
 		<div class="input">
 			<label for="software">Instance domain:</label>
 			<br class="sep"/>
-			<input type="text" name="instance"
-				class="w100" placeholder="example.org"/>
+			<div class="flex">
+				<input type="text" name="instance"
+					class="w100" placeholder="example.org"/>
+			</div>
 		</div>
 		<br>
 		<input class="btn green w100"
diff --git a/views/instance.php b/views/instance.php
index 632ac5c..a94f1d5 100644
--- a/views/instance.php
+++ b/views/instance.php
@@ -595,9 +595,12 @@ function load__instance(args) {
 
 		apcontrol_title(`Instance (${hargs['instance']})`);
 		const config = parse_ini_config(window.vars['current_instance']['config']);
-		const musthave = window.consts['instance_config'][hargs['software']]['musthave'];
-		for (var i = 0; i < musthave.length; i++) {
-			if (config[musthave[i]] === undefined) {
+		const fields = window.consts['instance_config'][hargs['software']]['fields'];
+		for (var i = 0; i < fields.length; i++) {
+			if (!fields[i].startsWith('*'))
+				continue;
+			const f = fields[i].substr(1);
+			if (config[f] === undefined) {
 				window.view.instance.show_config();
 				return false;
 			}
diff --git a/views/instance_config.php b/views/instance_config.php
index c13bd1e..7f1f5d3 100644
--- a/views/instance_config.php
+++ b/views/instance_config.php
@@ -13,7 +13,7 @@
 		</div>
 	</form>
 	<div id="config-item">
-		<label for="{field}">{placeholder}:</label>
+		<label for="{field}">{importantMark}{placeholder}:</label>
 		<input id="config_{field}" name="{field}" class="w100"
 			placeholder="{field}" type="text"/>
 	</div>
@@ -25,10 +25,11 @@ window.view.instance_config = {
 		mastodon: function(hargs, config) {
 			E.element('#window-instance_config form').setAttribute('action',
 				`api/v1/config/put/?software=mastodon&instance=${hargs['instance']}`);
-			const fields = window.consts['instance_config']['mastodon']['musthave'];
+			const fields = window.consts['instance_config']['mastodon']['fields'];
 			for (var i = 0; i < fields.length; i++) {
-				if (config[fields[i]] !== undefined)
-					E.elemid(`config_${fields[i]}`).value = config[fields[i]];
+				const f = fields[i].startsWith('*') ? fields[i].substr(1) : fields[i];
+				if (config[f] !== undefined)
+					E.elemid(`config_${f}`).value = config[f];
 			}
 			if (config['instance_url'] === undefined) {
 				http.get('api/v1/network/resolve-instance?hostname='+hargs['instance'],
@@ -54,11 +55,14 @@ function load__instance_config(args) {
 			capitalize(hargs['software']) + ` (${hargs['instance']})`);
 		E.template('config', function(TPL) {
 			var html = '';
-			const fields = window.consts['instance_config'][hargs['software']]['musthave'];
+			const fields = window.consts['instance_config'][hargs['software']]['fields'];
 			for (var i = 0; i < fields.length; i++) {
+				const field = fields[i].startsWith('*') ? fields[i].substr(1) : fields[i];
+				const important = fields[i].startsWith('*');
 				var tpl = TPL;
-				tpl = tpl.replaceAll('{field}',			fields[i]);
-				tpl = tpl.replaceAll('{placeholder}',	human_field_name(fields[i]));
+				tpl = tpl.replaceAll('{field}',			field);
+				tpl = tpl.replaceAll('{placeholder}',	human_field_name(field));
+				tpl = tpl.replaceAll('{importantMark}',	important ? '*' : '');
 				html += tpl;
 			}
 			return html;