diff --git a/settings/Controller/SecuritySettingsController.php b/settings/Controller/SecuritySettingsController.php
index 88b2803..5c6f174 100644
--- a/settings/Controller/SecuritySettingsController.php
+++ b/settings/Controller/SecuritySettingsController.php
@@ -60,7 +60,7 @@ protected function returnSuccess() {
 	 * @return array
 	 */
 	public function trustedDomains($newTrustedDomain) {
-		$trustedDomains = $this->config->getSystemValue('trusted_domains');
+		$trustedDomains = $this->config->getSystemValue('trusted_domains', []);
 		$trustedDomains[] = $newTrustedDomain;
 		$this->config->setSystemValue('trusted_domains', $trustedDomains);