diff --git a/mod/settings.php b/mod/settings.php
index 2f61a6e07..ba703db15 100644
--- a/mod/settings.php
+++ b/mod/settings.php
@@ -370,19 +370,19 @@ function settings_post(App $a)
 		PConfig::set(local_user(), 'system', 'bandwidth_saver'         , $bandwidth_saver);
 		PConfig::set(local_user(), 'system', 'smart_threading'         , $smart_threading);
 
-		if ($theme == $a->user['theme']) {
-			// call theme_post only if theme has not been changed
-			if (($themeconfigfile = get_theme_config_file($theme)) !== null) {
-				require_once $themeconfigfile;
-				theme_post($a);
+		if (in_array($theme, Theme::getAllowedList())) {
+			if ($theme == $a->user['theme']) {
+				// call theme_post only if theme has not been changed
+				if (($themeconfigfile = get_theme_config_file($theme)) !== null) {
+					require_once $themeconfigfile;
+					theme_post($a);
+				}
+			} else {
+				$a->getDatabase()->update('user', ['theme' => $theme], ['uid' => local_user()]);
 			}
+		} else {
+			notice(L10n::t('The theme you chose isn\'t available.'));
 		}
-		Theme::install($theme);
-
-		q("UPDATE `user` SET `theme` = '%s' WHERE `uid` = %d",
-				DBA::escape($theme),
-				intval(local_user())
-		);
 
 		Hook::callAll('display_settings_post', $_POST);
 		$a->internalRedirect('settings/display');
@@ -915,8 +915,8 @@ function settings_content(App $a)
 			}
 		}
 
-		$theme_selected        = Session::get('theme', $default_theme);
-		$mobile_theme_selected = Session::get('mobile-theme', $default_mobile_theme);
+		$theme_selected        = $a->user['theme'] ?: $default_theme;
+		$mobile_theme_selected = $a->user['mobile-theme'] ?: $default_mobile_theme;
 
 		$nowarn_insecure = intval(PConfig::get(local_user(), 'system', 'nowarn_insecure'));
 
diff --git a/view/theme/frio/config.php b/view/theme/frio/config.php
index d1591273f..0f3eda4c9 100644
--- a/view/theme/frio/config.php
+++ b/view/theme/frio/config.php
@@ -56,15 +56,17 @@ function theme_content(App $a)
 	}
 	$arr = [];
 
-	$arr['scheme']           = PConfig::get(local_user(), 'frio', 'scheme', PConfig::get(local_user(), 'frio', 'schema'));
+	$node_scheme = Config::get('frio', 'scheme', Config::get('frio', 'scheme'));
+
+	$arr['scheme']           = PConfig::get(local_user(), 'frio', 'scheme', PConfig::get(local_user(), 'frio', 'schema', $node_scheme));
 	$arr['share_string']     = '';
-	$arr['nav_bg']           = PConfig::get(local_user(), 'frio', 'nav_bg');
-	$arr['nav_icon_color']   = PConfig::get(local_user(), 'frio', 'nav_icon_color');
-	$arr['link_color']       = PConfig::get(local_user(), 'frio', 'link_color');
-	$arr['background_color'] = PConfig::get(local_user(), 'frio', 'background_color');
-	$arr['contentbg_transp'] = PConfig::get(local_user(), 'frio', 'contentbg_transp');
-	$arr['background_image'] = PConfig::get(local_user(), 'frio', 'background_image');
-	$arr['bg_image_option']  = PConfig::get(local_user(), 'frio', 'bg_image_option');
+	$arr['nav_bg']           = PConfig::get(local_user(), 'frio', 'nav_bg'          , Config::get('frio', 'nav_bg'));
+	$arr['nav_icon_color']   = PConfig::get(local_user(), 'frio', 'nav_icon_color'  , Config::get('frio', 'nav_icon_color'));
+	$arr['link_color']       = PConfig::get(local_user(), 'frio', 'link_color'      , Config::get('frio', 'link_color'));
+	$arr['background_color'] = PConfig::get(local_user(), 'frio', 'background_color', Config::get('frio', 'background_color'));
+	$arr['contentbg_transp'] = PConfig::get(local_user(), 'frio', 'contentbg_transp', Config::get('frio', 'contentbg_transp'));
+	$arr['background_image'] = PConfig::get(local_user(), 'frio', 'background_image', Config::get('frio', 'background_image'));
+	$arr['bg_image_option']  = PConfig::get(local_user(), 'frio', 'bg_image_option' , Config::get('frio', 'bg_image_option'));
 
 	return frio_form($arr);
 }