diff --git a/controllers/CalendarApiController.php b/controllers/CalendarApiController.php
index 183d6245..e20c3cb3 100644
--- a/controllers/CalendarApiController.php
+++ b/controllers/CalendarApiController.php
@@ -52,7 +52,7 @@ class CalendarApiController extends BaseApiController
 		try
 		{
 			return $this->ApiResponse($response, array(
-				'url' => $this->AppContainer->get('UrlManager')->ConstructUrl('/api/calendar/ical?secret=' . $this->getApiKeyService()->GetOrCreateApiKey(ApiKeyService::API_KEY_TYPE_SPECIAL_PURPOSE_CALENDAR_ICAL))
+				'url' => $this->AppContainer->get('UrlManager')->ConstructUrl('/api/calendar/ical?secret=' . $this->getApiKeyService()->GetOrCreateApiKey(\Grocy\Services\ApiKeyService::API_KEY_TYPE_SPECIAL_PURPOSE_CALENDAR_ICAL))
 			));
 		}
 		catch (\Exception $ex)