Spring Boot STRICT-DUPLICATE-DETECTION for Jackson3

[tklaus]

Hi everyone,

I am looking for a way to enable strict-duplicate-detection in Jackson3. I migrated our Spring Boot Application to Spring Boot 4.
In Spring Boot 3 I was able to configure it in the application.properties by setting spring.jackson.parser.strict-duplicate-detection=true, but this option is no longer available after migrating to SpringBoot 4.

[pjfanning]

Please ask the Spring team. Jackson has nothing to do with Spring.

[tklaus]

Thanks a lot for the immediate feedback. I will check!

[pjfanning]

https://spring.io/blog/2025/10/07/introducing-jackson-3-support-in-spring might be worth reading