| Q | A | ---------------- | ----- | Bug report? | yes | Feature request? | no | BC Break report? | yes | RFC? | no | Symfony version | first occurred in 3.3 <!-- - Please fill in this template according to your issue. - For support request or how-tos, visit https://symfony.com/support - Otherwise, replace this comment by the description of your issue. --> Symfony 3.2 is able to parse yaml that looks like this: ``` factory.keyvalue.expirable: {} # Default key/value expirable storage service to use. # @default keyvalue.database.expirable # default: keyvalue.database.expirable ``` Symfony 3.3+ it results in `Uncaught Symfony\Component\Yaml\Exception\ParseException: Unable to parse at line 2 (near "{}")` Using git bisect shows that this break was introduced by https://github.com/symfony/symfony/pull/25241