# Fluentd v1.20.1

> Observability · 2026-10-26

A targeted maintenance release removes the `yajl-ruby` runtime dependency for `Ruby 4.1`. Plugin users that rely on `require 'yajl'` need to declare or migrate that dependency.

## Check if affected
- **[breaking]** The `yajl-ruby` runtime dependency, removed for `Ruby 4.1`
  - Applies if you run `Ruby 4.1` and do not declare `yajl-ruby` as a dependency.
  - The runtime dependency on `yajl-ruby` is removed for `Ruby 4.1`. Plugins that `require 'yajl'` need to declare `yajl-ruby` in their own gemspec; adding it to the `Gemfile` addresses `LoadError: cannot load such file -- yajl` only on `Ruby 4.0` or earlier.

[Full analysis](https://ratatosk.io/en/releases/fluentd/v1.20.1)

[Original release notes](https://github.com/fluent/fluentd/releases/tag/v1.20.1)