diff --git a/src/Configuration.php b/src/Configuration.php
index df551e9c..2394a2ea 100644
--- a/src/Configuration.php
+++ b/src/Configuration.php
@@ -269,6 +269,9 @@ public function save(): void
 
         $securityConfig = $this->getSecurityConfig();
         if (($this->configuration['general']['active'] ?? false) && isset($securityConfig['method']) && $securityConfig['method'] === self::SECURITYCONFIG_AUTH_APIKEY) {
+            if (!is_array($securityConfig['apikey'])) {
+                $securityConfig['apikey'] = [$securityConfig['apikey']];
+            }
             foreach ($securityConfig['apikey'] as $apiKey) {
                 if (strlen($apiKey) < 16) {
                     throw new \Exception('API key ' . $apiKey . ' does not satisfy the minimum length of 16 characters');