diff --git a/grails-app/conf/Config.groovy b/grails-app/conf/Config.groovy
index ac16fc56c8..204199e4f7 100644
--- a/grails-app/conf/Config.groovy
+++ b/grails-app/conf/Config.groovy
@@ -188,7 +188,7 @@ environments {
  * API & CORS config
  */
 cors.url.pattern = ['/api/*', '/contact/send', '/profile/*', '/logout/*', '/login/*', '/j_spring_security_check', '/canvas', '/logout', '/j_spring_security_logout']
-cors.headers = ['Access-Control-Allow-Headers': 'origin, authorization, accept, content-type, x-requested-with, Streamr-Client']
+cors.headers = ['Access-Control-Allow-Headers': 'origin, authorization, accept, content-type, x-requested-with, Streamr-Client'] // allow custom Streamr-Client header in CORS requests
 
 streamr.apiKey.revokeNotificationStream = "revoked-api-keys"